LCOV - code coverage report
Current view: top level - src/backend/commands - dbcommands.c (source / functions) Hit Total Coverage
Test: PostgreSQL 19devel Lines: 928 1106 83.9 %
Date: 2025-09-15 21:18:02 Functions: 27 29 93.1 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * dbcommands.c
       4             :  *      Database management commands (create/drop database).
       5             :  *
       6             :  * Note: database creation/destruction commands use exclusive locks on
       7             :  * the database objects (as expressed by LockSharedObject()) to avoid
       8             :  * stepping on each others' toes.  Formerly we used table-level locks
       9             :  * on pg_database, but that's too coarse-grained.
      10             :  *
      11             :  * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
      12             :  * Portions Copyright (c) 1994, Regents of the University of California
      13             :  *
      14             :  *
      15             :  * IDENTIFICATION
      16             :  *    src/backend/commands/dbcommands.c
      17             :  *
      18             :  *-------------------------------------------------------------------------
      19             :  */
      20             : #include "postgres.h"
      21             : 
      22             : #include <fcntl.h>
      23             : #include <unistd.h>
      24             : #include <sys/stat.h>
      25             : 
      26             : #include "access/genam.h"
      27             : #include "access/heapam.h"
      28             : #include "access/htup_details.h"
      29             : #include "access/multixact.h"
      30             : #include "access/tableam.h"
      31             : #include "access/xact.h"
      32             : #include "access/xloginsert.h"
      33             : #include "access/xlogrecovery.h"
      34             : #include "access/xlogutils.h"
      35             : #include "catalog/catalog.h"
      36             : #include "catalog/dependency.h"
      37             : #include "catalog/indexing.h"
      38             : #include "catalog/objectaccess.h"
      39             : #include "catalog/pg_authid.h"
      40             : #include "catalog/pg_collation.h"
      41             : #include "catalog/pg_database.h"
      42             : #include "catalog/pg_db_role_setting.h"
      43             : #include "catalog/pg_subscription.h"
      44             : #include "catalog/pg_tablespace.h"
      45             : #include "commands/comment.h"
      46             : #include "commands/dbcommands.h"
      47             : #include "commands/dbcommands_xlog.h"
      48             : #include "commands/defrem.h"
      49             : #include "commands/seclabel.h"
      50             : #include "commands/tablespace.h"
      51             : #include "common/file_perm.h"
      52             : #include "mb/pg_wchar.h"
      53             : #include "miscadmin.h"
      54             : #include "pgstat.h"
      55             : #include "postmaster/bgwriter.h"
      56             : #include "replication/slot.h"
      57             : #include "storage/copydir.h"
      58             : #include "storage/fd.h"
      59             : #include "storage/ipc.h"
      60             : #include "storage/lmgr.h"
      61             : #include "storage/md.h"
      62             : #include "storage/procarray.h"
      63             : #include "storage/smgr.h"
      64             : #include "utils/acl.h"
      65             : #include "utils/builtins.h"
      66             : #include "utils/fmgroids.h"
      67             : #include "utils/lsyscache.h"
      68             : #include "utils/pg_locale.h"
      69             : #include "utils/relmapper.h"
      70             : #include "utils/snapmgr.h"
      71             : #include "utils/syscache.h"
      72             : 
      73             : /*
      74             :  * Create database strategy.
      75             :  *
      76             :  * CREATEDB_WAL_LOG will copy the database at the block level and WAL log each
      77             :  * copied block.
      78             :  *
      79             :  * CREATEDB_FILE_COPY will simply perform a file system level copy of the
      80             :  * database and log a single record for each tablespace copied. To make this
      81             :  * safe, it also triggers checkpoints before and after the operation.
      82             :  */
      83             : typedef enum CreateDBStrategy
      84             : {
      85             :     CREATEDB_WAL_LOG,
      86             :     CREATEDB_FILE_COPY,
      87             : } CreateDBStrategy;
      88             : 
      89             : typedef struct
      90             : {
      91             :     Oid         src_dboid;      /* source (template) DB */
      92             :     Oid         dest_dboid;     /* DB we are trying to create */
      93             :     CreateDBStrategy strategy;  /* create db strategy */
      94             : } createdb_failure_params;
      95             : 
      96             : typedef struct
      97             : {
      98             :     Oid         dest_dboid;     /* DB we are trying to move */
      99             :     Oid         dest_tsoid;     /* tablespace we are trying to move to */
     100             : } movedb_failure_params;
     101             : 
     102             : /*
     103             :  * Information about a relation to be copied when creating a database.
     104             :  */
     105             : typedef struct CreateDBRelInfo
     106             : {
     107             :     RelFileLocator rlocator;    /* physical relation identifier */
     108             :     Oid         reloid;         /* relation oid */
     109             :     bool        permanent;      /* relation is permanent or unlogged */
     110             : } CreateDBRelInfo;
     111             : 
     112             : 
     113             : /* non-export function prototypes */
     114             : static void createdb_failure_callback(int code, Datum arg);
     115             : static void movedb(const char *dbname, const char *tblspcname);
     116             : static void movedb_failure_callback(int code, Datum arg);
     117             : static bool get_db_info(const char *name, LOCKMODE lockmode,
     118             :                         Oid *dbIdP, Oid *ownerIdP,
     119             :                         int *encodingP, bool *dbIsTemplateP, bool *dbAllowConnP, bool *dbHasLoginEvtP,
     120             :                         TransactionId *dbFrozenXidP, MultiXactId *dbMinMultiP,
     121             :                         Oid *dbTablespace, char **dbCollate, char **dbCtype, char **dbLocale,
     122             :                         char **dbIcurules,
     123             :                         char *dbLocProvider,
     124             :                         char **dbCollversion);
     125             : static void remove_dbtablespaces(Oid db_id);
     126             : static bool check_db_file_conflict(Oid db_id);
     127             : static int  errdetail_busy_db(int notherbackends, int npreparedxacts);
     128             : static void CreateDatabaseUsingWalLog(Oid src_dboid, Oid dst_dboid, Oid src_tsid,
     129             :                                       Oid dst_tsid);
     130             : static List *ScanSourceDatabasePgClass(Oid tbid, Oid dbid, char *srcpath);
     131             : static List *ScanSourceDatabasePgClassPage(Page page, Buffer buf, Oid tbid,
     132             :                                            Oid dbid, char *srcpath,
     133             :                                            List *rlocatorlist, Snapshot snapshot);
     134             : static CreateDBRelInfo *ScanSourceDatabasePgClassTuple(HeapTupleData *tuple,
     135             :                                                        Oid tbid, Oid dbid,
     136             :                                                        char *srcpath);
     137             : static void CreateDirAndVersionFile(char *dbpath, Oid dbid, Oid tsid,
     138             :                                     bool isRedo);
     139             : static void CreateDatabaseUsingFileCopy(Oid src_dboid, Oid dst_dboid,
     140             :                                         Oid src_tsid, Oid dst_tsid);
     141             : static void recovery_create_dbdir(char *path, bool only_tblspc);
     142             : 
     143             : /*
     144             :  * Create a new database using the WAL_LOG strategy.
     145             :  *
     146             :  * Each copied block is separately written to the write-ahead log.
     147             :  */
     148             : static void
     149         496 : CreateDatabaseUsingWalLog(Oid src_dboid, Oid dst_dboid,
     150             :                           Oid src_tsid, Oid dst_tsid)
     151             : {
     152             :     char       *srcpath;
     153             :     char       *dstpath;
     154         496 :     List       *rlocatorlist = NULL;
     155             :     ListCell   *cell;
     156             :     LockRelId   srcrelid;
     157             :     LockRelId   dstrelid;
     158             :     RelFileLocator srcrlocator;
     159             :     RelFileLocator dstrlocator;
     160             :     CreateDBRelInfo *relinfo;
     161             : 
     162             :     /* Get source and destination database paths. */
     163         496 :     srcpath = GetDatabasePath(src_dboid, src_tsid);
     164         496 :     dstpath = GetDatabasePath(dst_dboid, dst_tsid);
     165             : 
     166             :     /* Create database directory and write PG_VERSION file. */
     167         496 :     CreateDirAndVersionFile(dstpath, dst_dboid, dst_tsid, false);
     168             : 
     169             :     /* Copy relmap file from source database to the destination database. */
     170         496 :     RelationMapCopy(dst_dboid, dst_tsid, srcpath, dstpath);
     171             : 
     172             :     /* Get list of relfilelocators to copy from the source database. */
     173         496 :     rlocatorlist = ScanSourceDatabasePgClass(src_tsid, src_dboid, srcpath);
     174             :     Assert(rlocatorlist != NIL);
     175             : 
     176             :     /*
     177             :      * Database IDs will be the same for all relations so set them before
     178             :      * entering the loop.
     179             :      */
     180         496 :     srcrelid.dbId = src_dboid;
     181         496 :     dstrelid.dbId = dst_dboid;
     182             : 
     183             :     /* Loop over our list of relfilelocators and copy each one. */
     184      110740 :     foreach(cell, rlocatorlist)
     185             :     {
     186      110248 :         relinfo = lfirst(cell);
     187      110248 :         srcrlocator = relinfo->rlocator;
     188             : 
     189             :         /*
     190             :          * If the relation is from the source db's default tablespace then we
     191             :          * need to create it in the destination db's default tablespace.
     192             :          * Otherwise, we need to create in the same tablespace as it is in the
     193             :          * source database.
     194             :          */
     195      110248 :         if (srcrlocator.spcOid == src_tsid)
     196      110248 :             dstrlocator.spcOid = dst_tsid;
     197             :         else
     198           0 :             dstrlocator.spcOid = srcrlocator.spcOid;
     199             : 
     200      110248 :         dstrlocator.dbOid = dst_dboid;
     201      110248 :         dstrlocator.relNumber = srcrlocator.relNumber;
     202             : 
     203             :         /*
     204             :          * Acquire locks on source and target relations before copying.
     205             :          *
     206             :          * We typically do not read relation data into shared_buffers without
     207             :          * holding a relation lock. It's unclear what could go wrong if we
     208             :          * skipped it in this case, because nobody can be modifying either the
     209             :          * source or destination database at this point, and we have locks on
     210             :          * both databases, too, but let's take the conservative route.
     211             :          */
     212      110248 :         dstrelid.relId = srcrelid.relId = relinfo->reloid;
     213      110248 :         LockRelationId(&srcrelid, AccessShareLock);
     214      110248 :         LockRelationId(&dstrelid, AccessShareLock);
     215             : 
     216             :         /* Copy relation storage from source to the destination. */
     217      110248 :         CreateAndCopyRelationData(srcrlocator, dstrlocator, relinfo->permanent);
     218             : 
     219             :         /* Release the relation locks. */
     220      110244 :         UnlockRelationId(&srcrelid, AccessShareLock);
     221      110244 :         UnlockRelationId(&dstrelid, AccessShareLock);
     222             :     }
     223             : 
     224         492 :     pfree(srcpath);
     225         492 :     pfree(dstpath);
     226         492 :     list_free_deep(rlocatorlist);
     227         492 : }
     228             : 
     229             : /*
     230             :  * Scan the pg_class table in the source database to identify the relations
     231             :  * that need to be copied to the destination database.
     232             :  *
     233             :  * This is an exception to the usual rule that cross-database access is
     234             :  * not possible. We can make it work here because we know that there are no
     235             :  * connections to the source database and (since there can't be prepared
     236             :  * transactions touching that database) no in-doubt tuples either. This
     237             :  * means that we don't need to worry about pruning removing anything from
     238             :  * under us, and we don't need to be too picky about our snapshot either.
     239             :  * As long as it sees all previously-committed XIDs as committed and all
     240             :  * aborted XIDs as aborted, we should be fine: nothing else is possible
     241             :  * here.
     242             :  *
     243             :  * We can't rely on the relcache for anything here, because that only knows
     244             :  * about the database to which we are connected, and can't handle access to
     245             :  * other databases. That also means we can't rely on the heap scan
     246             :  * infrastructure, which would be a bad idea anyway since it might try
     247             :  * to do things like HOT pruning which we definitely can't do safely in
     248             :  * a database to which we're not even connected.
     249             :  */
     250             : static List *
     251         496 : ScanSourceDatabasePgClass(Oid tbid, Oid dbid, char *srcpath)
     252             : {
     253             :     RelFileLocator rlocator;
     254             :     BlockNumber nblocks;
     255             :     BlockNumber blkno;
     256             :     Buffer      buf;
     257             :     RelFileNumber relfilenumber;
     258             :     Page        page;
     259         496 :     List       *rlocatorlist = NIL;
     260             :     LockRelId   relid;
     261             :     Snapshot    snapshot;
     262             :     SMgrRelation smgr;
     263             :     BufferAccessStrategy bstrategy;
     264             : 
     265             :     /* Get pg_class relfilenumber. */
     266         496 :     relfilenumber = RelationMapOidToFilenumberForDatabase(srcpath,
     267             :                                                           RelationRelationId);
     268             : 
     269             :     /* Don't read data into shared_buffers without holding a relation lock. */
     270         496 :     relid.dbId = dbid;
     271         496 :     relid.relId = RelationRelationId;
     272         496 :     LockRelationId(&relid, AccessShareLock);
     273             : 
     274             :     /* Prepare a RelFileLocator for the pg_class relation. */
     275         496 :     rlocator.spcOid = tbid;
     276         496 :     rlocator.dbOid = dbid;
     277         496 :     rlocator.relNumber = relfilenumber;
     278             : 
     279         496 :     smgr = smgropen(rlocator, INVALID_PROC_NUMBER);
     280         496 :     nblocks = smgrnblocks(smgr, MAIN_FORKNUM);
     281         496 :     smgrclose(smgr);
     282             : 
     283             :     /* Use a buffer access strategy since this is a bulk read operation. */
     284         496 :     bstrategy = GetAccessStrategy(BAS_BULKREAD);
     285             : 
     286             :     /*
     287             :      * As explained in the function header comments, we need a snapshot that
     288             :      * will see all committed transactions as committed, and our transaction
     289             :      * snapshot - or the active snapshot - might not be new enough for that,
     290             :      * but the return value of GetLatestSnapshot() should work fine.
     291             :      */
     292         496 :     snapshot = RegisterSnapshot(GetLatestSnapshot());
     293             : 
     294             :     /* Process the relation block by block. */
     295        7440 :     for (blkno = 0; blkno < nblocks; blkno++)
     296             :     {
     297        6944 :         CHECK_FOR_INTERRUPTS();
     298             : 
     299        6944 :         buf = ReadBufferWithoutRelcache(rlocator, MAIN_FORKNUM, blkno,
     300             :                                         RBM_NORMAL, bstrategy, true);
     301             : 
     302        6944 :         LockBuffer(buf, BUFFER_LOCK_SHARE);
     303        6944 :         page = BufferGetPage(buf);
     304        6944 :         if (PageIsNew(page) || PageIsEmpty(page))
     305             :         {
     306           0 :             UnlockReleaseBuffer(buf);
     307           0 :             continue;
     308             :         }
     309             : 
     310             :         /* Append relevant pg_class tuples for current page to rlocatorlist. */
     311        6944 :         rlocatorlist = ScanSourceDatabasePgClassPage(page, buf, tbid, dbid,
     312             :                                                      srcpath, rlocatorlist,
     313             :                                                      snapshot);
     314             : 
     315        6944 :         UnlockReleaseBuffer(buf);
     316             :     }
     317         496 :     UnregisterSnapshot(snapshot);
     318             : 
     319             :     /* Release relation lock. */
     320         496 :     UnlockRelationId(&relid, AccessShareLock);
     321             : 
     322         496 :     return rlocatorlist;
     323             : }
     324             : 
     325             : /*
     326             :  * Scan one page of the source database's pg_class relation and add relevant
     327             :  * entries to rlocatorlist. The return value is the updated list.
     328             :  */
     329             : static List *
     330        6944 : ScanSourceDatabasePgClassPage(Page page, Buffer buf, Oid tbid, Oid dbid,
     331             :                               char *srcpath, List *rlocatorlist,
     332             :                               Snapshot snapshot)
     333             : {
     334        6944 :     BlockNumber blkno = BufferGetBlockNumber(buf);
     335             :     OffsetNumber offnum;
     336             :     OffsetNumber maxoff;
     337             :     HeapTupleData tuple;
     338             : 
     339        6944 :     maxoff = PageGetMaxOffsetNumber(page);
     340             : 
     341             :     /* Loop over offsets. */
     342        6944 :     for (offnum = FirstOffsetNumber;
     343      355318 :          offnum <= maxoff;
     344      348374 :          offnum = OffsetNumberNext(offnum))
     345             :     {
     346             :         ItemId      itemid;
     347             : 
     348      348374 :         itemid = PageGetItemId(page, offnum);
     349             : 
     350             :         /* Nothing to do if slot is empty or already dead. */
     351      348374 :         if (!ItemIdIsUsed(itemid) || ItemIdIsDead(itemid) ||
     352      249558 :             ItemIdIsRedirected(itemid))
     353      141968 :             continue;
     354             : 
     355             :         Assert(ItemIdIsNormal(itemid));
     356      206406 :         ItemPointerSet(&(tuple.t_self), blkno, offnum);
     357             : 
     358             :         /* Initialize a HeapTupleData structure. */
     359      206406 :         tuple.t_data = (HeapTupleHeader) PageGetItem(page, itemid);
     360      206406 :         tuple.t_len = ItemIdGetLength(itemid);
     361      206406 :         tuple.t_tableOid = RelationRelationId;
     362             : 
     363             :         /* Skip tuples that are not visible to this snapshot. */
     364      206406 :         if (HeapTupleSatisfiesVisibility(&tuple, snapshot, buf))
     365             :         {
     366             :             CreateDBRelInfo *relinfo;
     367             : 
     368             :             /*
     369             :              * ScanSourceDatabasePgClassTuple is in charge of constructing a
     370             :              * CreateDBRelInfo object for this tuple, but can also decide that
     371             :              * this tuple isn't something we need to copy. If we do need to
     372             :              * copy the relation, add it to the list.
     373             :              */
     374      206376 :             relinfo = ScanSourceDatabasePgClassTuple(&tuple, tbid, dbid,
     375             :                                                      srcpath);
     376      206376 :             if (relinfo != NULL)
     377      111144 :                 rlocatorlist = lappend(rlocatorlist, relinfo);
     378             :         }
     379             :     }
     380             : 
     381        6944 :     return rlocatorlist;
     382             : }
     383             : 
     384             : /*
     385             :  * Decide whether a certain pg_class tuple represents something that
     386             :  * needs to be copied from the source database to the destination database,
     387             :  * and if so, construct a CreateDBRelInfo for it.
     388             :  *
     389             :  * Visibility checks are handled by the caller, so our job here is just
     390             :  * to assess the data stored in the tuple.
     391             :  */
     392             : CreateDBRelInfo *
     393      206376 : ScanSourceDatabasePgClassTuple(HeapTupleData *tuple, Oid tbid, Oid dbid,
     394             :                                char *srcpath)
     395             : {
     396             :     CreateDBRelInfo *relinfo;
     397             :     Form_pg_class classForm;
     398      206376 :     RelFileNumber relfilenumber = InvalidRelFileNumber;
     399             : 
     400      206376 :     classForm = (Form_pg_class) GETSTRUCT(tuple);
     401             : 
     402             :     /*
     403             :      * Return NULL if this object does not need to be copied.
     404             :      *
     405             :      * Shared objects don't need to be copied, because they are shared.
     406             :      * Objects without storage can't be copied, because there's nothing to
     407             :      * copy. Temporary relations don't need to be copied either, because they
     408             :      * are inaccessible outside of the session that created them, which must
     409             :      * be gone already, and couldn't connect to a different database if it
     410             :      * still existed. autovacuum will eventually remove the pg_class entries
     411             :      * as well.
     412             :      */
     413      206376 :     if (classForm->reltablespace == GLOBALTABLESPACE_OID ||
     414      183560 :         !RELKIND_HAS_STORAGE(classForm->relkind) ||
     415      111144 :         classForm->relpersistence == RELPERSISTENCE_TEMP)
     416       95232 :         return NULL;
     417             : 
     418             :     /*
     419             :      * If relfilenumber is valid then directly use it.  Otherwise, consult the
     420             :      * relmap.
     421             :      */
     422      111144 :     if (RelFileNumberIsValid(classForm->relfilenode))
     423      102712 :         relfilenumber = classForm->relfilenode;
     424             :     else
     425        8432 :         relfilenumber = RelationMapOidToFilenumberForDatabase(srcpath,
     426             :                                                               classForm->oid);
     427             : 
     428             :     /* We must have a valid relfilenumber. */
     429      111144 :     if (!RelFileNumberIsValid(relfilenumber))
     430           0 :         elog(ERROR, "relation with OID %u does not have a valid relfilenumber",
     431             :              classForm->oid);
     432             : 
     433             :     /* Prepare a rel info element and add it to the list. */
     434      111144 :     relinfo = (CreateDBRelInfo *) palloc(sizeof(CreateDBRelInfo));
     435      111144 :     if (OidIsValid(classForm->reltablespace))
     436           0 :         relinfo->rlocator.spcOid = classForm->reltablespace;
     437             :     else
     438      111144 :         relinfo->rlocator.spcOid = tbid;
     439             : 
     440      111144 :     relinfo->rlocator.dbOid = dbid;
     441      111144 :     relinfo->rlocator.relNumber = relfilenumber;
     442      111144 :     relinfo->reloid = classForm->oid;
     443             : 
     444             :     /* Temporary relations were rejected above. */
     445             :     Assert(classForm->relpersistence != RELPERSISTENCE_TEMP);
     446      111144 :     relinfo->permanent =
     447      111144 :         (classForm->relpersistence == RELPERSISTENCE_PERMANENT) ? true : false;
     448             : 
     449      111144 :     return relinfo;
     450             : }
     451             : 
     452             : /*
     453             :  * Create database directory and write out the PG_VERSION file in the database
     454             :  * path.  If isRedo is true, it's okay for the database directory to exist
     455             :  * already.
     456             :  */
     457             : static void
     458         542 : CreateDirAndVersionFile(char *dbpath, Oid dbid, Oid tsid, bool isRedo)
     459             : {
     460             :     int         fd;
     461             :     int         nbytes;
     462             :     char        versionfile[MAXPGPATH];
     463             :     char        buf[16];
     464             : 
     465             :     /*
     466             :      * Note that we don't have to copy version data from the source database;
     467             :      * there's only one legal value.
     468             :      */
     469         542 :     sprintf(buf, "%s\n", PG_MAJORVERSION);
     470         542 :     nbytes = strlen(PG_MAJORVERSION) + 1;
     471             : 
     472             :     /* Create database directory. */
     473         542 :     if (MakePGDirectory(dbpath) < 0)
     474             :     {
     475             :         /* Failure other than already exists or not in WAL replay? */
     476          16 :         if (errno != EEXIST || !isRedo)
     477           0 :             ereport(ERROR,
     478             :                     (errcode_for_file_access(),
     479             :                      errmsg("could not create directory \"%s\": %m", dbpath)));
     480             :     }
     481             : 
     482             :     /*
     483             :      * Create PG_VERSION file in the database path.  If the file already
     484             :      * exists and we are in WAL replay then try again to open it in write
     485             :      * mode.
     486             :      */
     487         542 :     snprintf(versionfile, sizeof(versionfile), "%s/%s", dbpath, "PG_VERSION");
     488             : 
     489         542 :     fd = OpenTransientFile(versionfile, O_WRONLY | O_CREAT | O_EXCL | PG_BINARY);
     490         542 :     if (fd < 0 && errno == EEXIST && isRedo)
     491          16 :         fd = OpenTransientFile(versionfile, O_WRONLY | O_TRUNC | PG_BINARY);
     492             : 
     493         542 :     if (fd < 0)
     494           0 :         ereport(ERROR,
     495             :                 (errcode_for_file_access(),
     496             :                  errmsg("could not create file \"%s\": %m", versionfile)));
     497             : 
     498             :     /* Write PG_MAJORVERSION in the PG_VERSION file. */
     499         542 :     pgstat_report_wait_start(WAIT_EVENT_VERSION_FILE_WRITE);
     500         542 :     errno = 0;
     501         542 :     if ((int) write(fd, buf, nbytes) != nbytes)
     502             :     {
     503             :         /* If write didn't set errno, assume problem is no disk space. */
     504           0 :         if (errno == 0)
     505           0 :             errno = ENOSPC;
     506           0 :         ereport(ERROR,
     507             :                 (errcode_for_file_access(),
     508             :                  errmsg("could not write to file \"%s\": %m", versionfile)));
     509             :     }
     510         542 :     pgstat_report_wait_end();
     511             : 
     512         542 :     pgstat_report_wait_start(WAIT_EVENT_VERSION_FILE_SYNC);
     513         542 :     if (pg_fsync(fd) != 0)
     514           0 :         ereport(data_sync_elevel(ERROR),
     515             :                 (errcode_for_file_access(),
     516             :                  errmsg("could not fsync file \"%s\": %m", versionfile)));
     517         542 :     fsync_fname(dbpath, true);
     518         542 :     pgstat_report_wait_end();
     519             : 
     520             :     /* Close the version file. */
     521         542 :     CloseTransientFile(fd);
     522             : 
     523             :     /* If we are not in WAL replay then write the WAL. */
     524         542 :     if (!isRedo)
     525             :     {
     526             :         xl_dbase_create_wal_log_rec xlrec;
     527             : 
     528         496 :         START_CRIT_SECTION();
     529             : 
     530         496 :         xlrec.db_id = dbid;
     531         496 :         xlrec.tablespace_id = tsid;
     532             : 
     533         496 :         XLogBeginInsert();
     534         496 :         XLogRegisterData(&xlrec,
     535             :                          sizeof(xl_dbase_create_wal_log_rec));
     536             : 
     537         496 :         (void) XLogInsert(RM_DBASE_ID, XLOG_DBASE_CREATE_WAL_LOG);
     538             : 
     539         496 :         END_CRIT_SECTION();
     540             :     }
     541         542 : }
     542             : 
     543             : /*
     544             :  * Create a new database using the FILE_COPY strategy.
     545             :  *
     546             :  * Copy each tablespace at the filesystem level, and log a single WAL record
     547             :  * for each tablespace copied.  This requires a checkpoint before and after the
     548             :  * copy, which may be expensive, but it does greatly reduce WAL generation
     549             :  * if the copied database is large.
     550             :  */
     551             : static void
     552         268 : CreateDatabaseUsingFileCopy(Oid src_dboid, Oid dst_dboid, Oid src_tsid,
     553             :                             Oid dst_tsid)
     554             : {
     555             :     TableScanDesc scan;
     556             :     Relation    rel;
     557             :     HeapTuple   tuple;
     558             : 
     559             :     /*
     560             :      * Force a checkpoint before starting the copy. This will force all dirty
     561             :      * buffers, including those of unlogged tables, out to disk, to ensure
     562             :      * source database is up-to-date on disk for the copy.
     563             :      * FlushDatabaseBuffers() would suffice for that, but we also want to
     564             :      * process any pending unlink requests. Otherwise, if a checkpoint
     565             :      * happened while we're copying files, a file might be deleted just when
     566             :      * we're about to copy it, causing the lstat() call in copydir() to fail
     567             :      * with ENOENT.
     568             :      *
     569             :      * In binary upgrade mode, we can skip this checkpoint because pg_upgrade
     570             :      * is careful to ensure that template0 is fully written to disk prior to
     571             :      * any CREATE DATABASE commands.
     572             :      */
     573         268 :     if (!IsBinaryUpgrade)
     574         212 :         RequestCheckpoint(CHECKPOINT_FAST | CHECKPOINT_FORCE |
     575             :                           CHECKPOINT_WAIT | CHECKPOINT_FLUSH_UNLOGGED);
     576             : 
     577             :     /*
     578             :      * Iterate through all tablespaces of the template database, and copy each
     579             :      * one to the new database.
     580             :      */
     581         268 :     rel = table_open(TableSpaceRelationId, AccessShareLock);
     582         268 :     scan = table_beginscan_catalog(rel, 0, NULL);
     583         872 :     while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
     584             :     {
     585         604 :         Form_pg_tablespace spaceform = (Form_pg_tablespace) GETSTRUCT(tuple);
     586         604 :         Oid         srctablespace = spaceform->oid;
     587             :         Oid         dsttablespace;
     588             :         char       *srcpath;
     589             :         char       *dstpath;
     590             :         struct stat st;
     591             : 
     592             :         /* No need to copy global tablespace */
     593         604 :         if (srctablespace == GLOBALTABLESPACE_OID)
     594         336 :             continue;
     595             : 
     596         336 :         srcpath = GetDatabasePath(src_dboid, srctablespace);
     597             : 
     598         604 :         if (stat(srcpath, &st) < 0 || !S_ISDIR(st.st_mode) ||
     599         268 :             directory_is_empty(srcpath))
     600             :         {
     601             :             /* Assume we can ignore it */
     602          68 :             pfree(srcpath);
     603          68 :             continue;
     604             :         }
     605             : 
     606         268 :         if (srctablespace == src_tsid)
     607         268 :             dsttablespace = dst_tsid;
     608             :         else
     609           0 :             dsttablespace = srctablespace;
     610             : 
     611         268 :         dstpath = GetDatabasePath(dst_dboid, dsttablespace);
     612             : 
     613             :         /*
     614             :          * Copy this subdirectory to the new location
     615             :          *
     616             :          * We don't need to copy subdirectories
     617             :          */
     618         268 :         copydir(srcpath, dstpath, false);
     619             : 
     620             :         /* Record the filesystem change in XLOG */
     621             :         {
     622             :             xl_dbase_create_file_copy_rec xlrec;
     623             : 
     624         268 :             xlrec.db_id = dst_dboid;
     625         268 :             xlrec.tablespace_id = dsttablespace;
     626         268 :             xlrec.src_db_id = src_dboid;
     627         268 :             xlrec.src_tablespace_id = srctablespace;
     628             : 
     629         268 :             XLogBeginInsert();
     630         268 :             XLogRegisterData(&xlrec,
     631             :                              sizeof(xl_dbase_create_file_copy_rec));
     632             : 
     633         268 :             (void) XLogInsert(RM_DBASE_ID,
     634             :                               XLOG_DBASE_CREATE_FILE_COPY | XLR_SPECIAL_REL_UPDATE);
     635             :         }
     636         268 :         pfree(srcpath);
     637         268 :         pfree(dstpath);
     638             :     }
     639         268 :     table_endscan(scan);
     640         268 :     table_close(rel, AccessShareLock);
     641             : 
     642             :     /*
     643             :      * We force a checkpoint before committing.  This effectively means that
     644             :      * committed XLOG_DBASE_CREATE_FILE_COPY operations will never need to be
     645             :      * replayed (at least not in ordinary crash recovery; we still have to
     646             :      * make the XLOG entry for the benefit of PITR operations). This avoids
     647             :      * two nasty scenarios:
     648             :      *
     649             :      * #1: At wal_level=minimal, we don't XLOG the contents of newly created
     650             :      * relfilenodes; therefore the drop-and-recreate-whole-directory behavior
     651             :      * of DBASE_CREATE replay would lose such files created in the new
     652             :      * database between our commit and the next checkpoint.
     653             :      *
     654             :      * #2: Since we have to recopy the source database during DBASE_CREATE
     655             :      * replay, we run the risk of copying changes in it that were committed
     656             :      * after the original CREATE DATABASE command but before the system crash
     657             :      * that led to the replay.  This is at least unexpected and at worst could
     658             :      * lead to inconsistencies, eg duplicate table names.
     659             :      *
     660             :      * (Both of these were real bugs in releases 8.0 through 8.0.3.)
     661             :      *
     662             :      * In PITR replay, the first of these isn't an issue, and the second is
     663             :      * only a risk if the CREATE DATABASE and subsequent template database
     664             :      * change both occur while a base backup is being taken. There doesn't
     665             :      * seem to be much we can do about that except document it as a
     666             :      * limitation.
     667             :      *
     668             :      * In binary upgrade mode, we can skip this checkpoint because neither of
     669             :      * these problems applies: we don't ever replay the WAL generated during
     670             :      * pg_upgrade, and we don't support taking base backups during pg_upgrade
     671             :      * (not to mention that we don't concurrently modify template0, either).
     672             :      *
     673             :      * See CreateDatabaseUsingWalLog() for a less cheesy CREATE DATABASE
     674             :      * strategy that avoids these problems.
     675             :      */
     676         268 :     if (!IsBinaryUpgrade)
     677         212 :         RequestCheckpoint(CHECKPOINT_FAST | CHECKPOINT_FORCE |
     678             :                           CHECKPOINT_WAIT);
     679         268 : }
     680             : 
     681             : /*
     682             :  * CREATE DATABASE
     683             :  */
     684             : Oid
     685         798 : createdb(ParseState *pstate, const CreatedbStmt *stmt)
     686             : {
     687             :     Oid         src_dboid;
     688             :     Oid         src_owner;
     689         798 :     int         src_encoding = -1;
     690         798 :     char       *src_collate = NULL;
     691         798 :     char       *src_ctype = NULL;
     692         798 :     char       *src_locale = NULL;
     693         798 :     char       *src_icurules = NULL;
     694         798 :     char        src_locprovider = '\0';
     695         798 :     char       *src_collversion = NULL;
     696             :     bool        src_istemplate;
     697         798 :     bool        src_hasloginevt = false;
     698             :     bool        src_allowconn;
     699         798 :     TransactionId src_frozenxid = InvalidTransactionId;
     700         798 :     MultiXactId src_minmxid = InvalidMultiXactId;
     701             :     Oid         src_deftablespace;
     702             :     volatile Oid dst_deftablespace;
     703             :     Relation    pg_database_rel;
     704             :     HeapTuple   tuple;
     705         798 :     Datum       new_record[Natts_pg_database] = {0};
     706         798 :     bool        new_record_nulls[Natts_pg_database] = {0};
     707         798 :     Oid         dboid = InvalidOid;
     708             :     Oid         datdba;
     709             :     ListCell   *option;
     710         798 :     DefElem    *tablespacenameEl = NULL;
     711         798 :     DefElem    *ownerEl = NULL;
     712         798 :     DefElem    *templateEl = NULL;
     713         798 :     DefElem    *encodingEl = NULL;
     714         798 :     DefElem    *localeEl = NULL;
     715         798 :     DefElem    *builtinlocaleEl = NULL;
     716         798 :     DefElem    *collateEl = NULL;
     717         798 :     DefElem    *ctypeEl = NULL;
     718         798 :     DefElem    *iculocaleEl = NULL;
     719         798 :     DefElem    *icurulesEl = NULL;
     720         798 :     DefElem    *locproviderEl = NULL;
     721         798 :     DefElem    *istemplateEl = NULL;
     722         798 :     DefElem    *allowconnectionsEl = NULL;
     723         798 :     DefElem    *connlimitEl = NULL;
     724         798 :     DefElem    *collversionEl = NULL;
     725         798 :     DefElem    *strategyEl = NULL;
     726         798 :     char       *dbname = stmt->dbname;
     727         798 :     char       *dbowner = NULL;
     728         798 :     const char *dbtemplate = NULL;
     729         798 :     char       *dbcollate = NULL;
     730         798 :     char       *dbctype = NULL;
     731         798 :     const char *dblocale = NULL;
     732         798 :     char       *dbicurules = NULL;
     733         798 :     char        dblocprovider = '\0';
     734             :     char       *canonname;
     735         798 :     int         encoding = -1;
     736         798 :     bool        dbistemplate = false;
     737         798 :     bool        dballowconnections = true;
     738         798 :     int         dbconnlimit = DATCONNLIMIT_UNLIMITED;
     739         798 :     char       *dbcollversion = NULL;
     740             :     int         notherbackends;
     741             :     int         npreparedxacts;
     742         798 :     CreateDBStrategy dbstrategy = CREATEDB_WAL_LOG;
     743             :     createdb_failure_params fparms;
     744             : 
     745             :     /* Extract options from the statement node tree */
     746        2382 :     foreach(option, stmt->options)
     747             :     {
     748        1584 :         DefElem    *defel = (DefElem *) lfirst(option);
     749             : 
     750        1584 :         if (strcmp(defel->defname, "tablespace") == 0)
     751             :         {
     752          34 :             if (tablespacenameEl)
     753           0 :                 errorConflictingDefElem(defel, pstate);
     754          34 :             tablespacenameEl = defel;
     755             :         }
     756        1550 :         else if (strcmp(defel->defname, "owner") == 0)
     757             :         {
     758           2 :             if (ownerEl)
     759           0 :                 errorConflictingDefElem(defel, pstate);
     760           2 :             ownerEl = defel;
     761             :         }
     762        1548 :         else if (strcmp(defel->defname, "template") == 0)
     763             :         {
     764         354 :             if (templateEl)
     765           0 :                 errorConflictingDefElem(defel, pstate);
     766         354 :             templateEl = defel;
     767             :         }
     768        1194 :         else if (strcmp(defel->defname, "encoding") == 0)
     769             :         {
     770         104 :             if (encodingEl)
     771           0 :                 errorConflictingDefElem(defel, pstate);
     772         104 :             encodingEl = defel;
     773             :         }
     774        1090 :         else if (strcmp(defel->defname, "locale") == 0)
     775             :         {
     776         106 :             if (localeEl)
     777           0 :                 errorConflictingDefElem(defel, pstate);
     778         106 :             localeEl = defel;
     779             :         }
     780         984 :         else if (strcmp(defel->defname, "builtin_locale") == 0)
     781             :         {
     782          16 :             if (builtinlocaleEl)
     783           0 :                 errorConflictingDefElem(defel, pstate);
     784          16 :             builtinlocaleEl = defel;
     785             :         }
     786         968 :         else if (strcmp(defel->defname, "lc_collate") == 0)
     787             :         {
     788          18 :             if (collateEl)
     789           0 :                 errorConflictingDefElem(defel, pstate);
     790          18 :             collateEl = defel;
     791             :         }
     792         950 :         else if (strcmp(defel->defname, "lc_ctype") == 0)
     793             :         {
     794          18 :             if (ctypeEl)
     795           0 :                 errorConflictingDefElem(defel, pstate);
     796          18 :             ctypeEl = defel;
     797             :         }
     798         932 :         else if (strcmp(defel->defname, "icu_locale") == 0)
     799             :         {
     800          10 :             if (iculocaleEl)
     801           0 :                 errorConflictingDefElem(defel, pstate);
     802          10 :             iculocaleEl = defel;
     803             :         }
     804         922 :         else if (strcmp(defel->defname, "icu_rules") == 0)
     805             :         {
     806           2 :             if (icurulesEl)
     807           0 :                 errorConflictingDefElem(defel, pstate);
     808           2 :             icurulesEl = defel;
     809             :         }
     810         920 :         else if (strcmp(defel->defname, "locale_provider") == 0)
     811             :         {
     812         116 :             if (locproviderEl)
     813           0 :                 errorConflictingDefElem(defel, pstate);
     814         116 :             locproviderEl = defel;
     815             :         }
     816         804 :         else if (strcmp(defel->defname, "is_template") == 0)
     817             :         {
     818         100 :             if (istemplateEl)
     819           0 :                 errorConflictingDefElem(defel, pstate);
     820         100 :             istemplateEl = defel;
     821             :         }
     822         704 :         else if (strcmp(defel->defname, "allow_connections") == 0)
     823             :         {
     824          98 :             if (allowconnectionsEl)
     825           0 :                 errorConflictingDefElem(defel, pstate);
     826          98 :             allowconnectionsEl = defel;
     827             :         }
     828         606 :         else if (strcmp(defel->defname, "connection_limit") == 0)
     829             :         {
     830           0 :             if (connlimitEl)
     831           0 :                 errorConflictingDefElem(defel, pstate);
     832           0 :             connlimitEl = defel;
     833             :         }
     834         606 :         else if (strcmp(defel->defname, "collation_version") == 0)
     835             :         {
     836          56 :             if (collversionEl)
     837           0 :                 errorConflictingDefElem(defel, pstate);
     838          56 :             collversionEl = defel;
     839             :         }
     840         550 :         else if (strcmp(defel->defname, "location") == 0)
     841             :         {
     842           0 :             ereport(WARNING,
     843             :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     844             :                      errmsg("LOCATION is not supported anymore"),
     845             :                      errhint("Consider using tablespaces instead."),
     846             :                      parser_errposition(pstate, defel->location)));
     847             :         }
     848         550 :         else if (strcmp(defel->defname, "oid") == 0)
     849             :         {
     850         258 :             dboid = defGetObjectId(defel);
     851             : 
     852             :             /*
     853             :              * We don't normally permit new databases to be created with
     854             :              * system-assigned OIDs. pg_upgrade tries to preserve database
     855             :              * OIDs, so we can't allow any database to be created with an OID
     856             :              * that might be in use in a freshly-initialized cluster created
     857             :              * by some future version. We assume all such OIDs will be from
     858             :              * the system-managed OID range.
     859             :              *
     860             :              * As an exception, however, we permit any OID to be assigned when
     861             :              * allow_system_table_mods=on (so that initdb can assign system
     862             :              * OIDs to template0 and postgres) or when performing a binary
     863             :              * upgrade (so that pg_upgrade can preserve whatever OIDs it finds
     864             :              * in the source cluster).
     865             :              */
     866         258 :             if (dboid < FirstNormalObjectId &&
     867         224 :                 !allowSystemTableMods && !IsBinaryUpgrade)
     868           0 :                 ereport(ERROR,
     869             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE)),
     870             :                         errmsg("OIDs less than %u are reserved for system objects", FirstNormalObjectId));
     871             :         }
     872         292 :         else if (strcmp(defel->defname, "strategy") == 0)
     873             :         {
     874         292 :             if (strategyEl)
     875           0 :                 errorConflictingDefElem(defel, pstate);
     876         292 :             strategyEl = defel;
     877             :         }
     878             :         else
     879           0 :             ereport(ERROR,
     880             :                     (errcode(ERRCODE_SYNTAX_ERROR),
     881             :                      errmsg("option \"%s\" not recognized", defel->defname),
     882             :                      parser_errposition(pstate, defel->location)));
     883             :     }
     884             : 
     885         798 :     if (ownerEl && ownerEl->arg)
     886           2 :         dbowner = defGetString(ownerEl);
     887         798 :     if (templateEl && templateEl->arg)
     888         354 :         dbtemplate = defGetString(templateEl);
     889         798 :     if (encodingEl && encodingEl->arg)
     890             :     {
     891             :         const char *encoding_name;
     892             : 
     893         104 :         if (IsA(encodingEl->arg, Integer))
     894             :         {
     895           0 :             encoding = defGetInt32(encodingEl);
     896           0 :             encoding_name = pg_encoding_to_char(encoding);
     897           0 :             if (strcmp(encoding_name, "") == 0 ||
     898           0 :                 pg_valid_server_encoding(encoding_name) < 0)
     899           0 :                 ereport(ERROR,
     900             :                         (errcode(ERRCODE_UNDEFINED_OBJECT),
     901             :                          errmsg("%d is not a valid encoding code",
     902             :                                 encoding),
     903             :                          parser_errposition(pstate, encodingEl->location)));
     904             :         }
     905             :         else
     906             :         {
     907         104 :             encoding_name = defGetString(encodingEl);
     908         104 :             encoding = pg_valid_server_encoding(encoding_name);
     909         104 :             if (encoding < 0)
     910           0 :                 ereport(ERROR,
     911             :                         (errcode(ERRCODE_UNDEFINED_OBJECT),
     912             :                          errmsg("%s is not a valid encoding name",
     913             :                                 encoding_name),
     914             :                          parser_errposition(pstate, encodingEl->location)));
     915             :         }
     916             :     }
     917         798 :     if (localeEl && localeEl->arg)
     918             :     {
     919         106 :         dbcollate = defGetString(localeEl);
     920         106 :         dbctype = defGetString(localeEl);
     921         106 :         dblocale = defGetString(localeEl);
     922             :     }
     923         798 :     if (builtinlocaleEl && builtinlocaleEl->arg)
     924          16 :         dblocale = defGetString(builtinlocaleEl);
     925         798 :     if (collateEl && collateEl->arg)
     926          18 :         dbcollate = defGetString(collateEl);
     927         798 :     if (ctypeEl && ctypeEl->arg)
     928          18 :         dbctype = defGetString(ctypeEl);
     929         798 :     if (iculocaleEl && iculocaleEl->arg)
     930          10 :         dblocale = defGetString(iculocaleEl);
     931         798 :     if (icurulesEl && icurulesEl->arg)
     932           2 :         dbicurules = defGetString(icurulesEl);
     933         798 :     if (locproviderEl && locproviderEl->arg)
     934             :     {
     935         116 :         char       *locproviderstr = defGetString(locproviderEl);
     936             : 
     937         116 :         if (pg_strcasecmp(locproviderstr, "builtin") == 0)
     938          34 :             dblocprovider = COLLPROVIDER_BUILTIN;
     939          82 :         else if (pg_strcasecmp(locproviderstr, "icu") == 0)
     940          16 :             dblocprovider = COLLPROVIDER_ICU;
     941          66 :         else if (pg_strcasecmp(locproviderstr, "libc") == 0)
     942          64 :             dblocprovider = COLLPROVIDER_LIBC;
     943             :         else
     944           2 :             ereport(ERROR,
     945             :                     (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
     946             :                      errmsg("unrecognized locale provider: %s",
     947             :                             locproviderstr)));
     948             :     }
     949         796 :     if (istemplateEl && istemplateEl->arg)
     950         100 :         dbistemplate = defGetBoolean(istemplateEl);
     951         796 :     if (allowconnectionsEl && allowconnectionsEl->arg)
     952          98 :         dballowconnections = defGetBoolean(allowconnectionsEl);
     953         796 :     if (connlimitEl && connlimitEl->arg)
     954             :     {
     955           0 :         dbconnlimit = defGetInt32(connlimitEl);
     956           0 :         if (dbconnlimit < DATCONNLIMIT_UNLIMITED)
     957           0 :             ereport(ERROR,
     958             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     959             :                      errmsg("invalid connection limit: %d", dbconnlimit)));
     960             :     }
     961         796 :     if (collversionEl)
     962          56 :         dbcollversion = defGetString(collversionEl);
     963             : 
     964             :     /* obtain OID of proposed owner */
     965         796 :     if (dbowner)
     966           2 :         datdba = get_role_oid(dbowner, false);
     967             :     else
     968         794 :         datdba = GetUserId();
     969             : 
     970             :     /*
     971             :      * To create a database, must have createdb privilege and must be able to
     972             :      * become the target role (this does not imply that the target role itself
     973             :      * must have createdb privilege).  The latter provision guards against
     974             :      * "giveaway" attacks.  Note that a superuser will always have both of
     975             :      * these privileges a fortiori.
     976             :      */
     977         796 :     if (!have_createdb_privilege())
     978           6 :         ereport(ERROR,
     979             :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     980             :                  errmsg("permission denied to create database")));
     981             : 
     982         790 :     check_can_set_role(GetUserId(), datdba);
     983             : 
     984             :     /*
     985             :      * Lookup database (template) to be cloned, and obtain share lock on it.
     986             :      * ShareLock allows two CREATE DATABASEs to work from the same template
     987             :      * concurrently, while ensuring no one is busy dropping it in parallel
     988             :      * (which would be Very Bad since we'd likely get an incomplete copy
     989             :      * without knowing it).  This also prevents any new connections from being
     990             :      * made to the source until we finish copying it, so we can be sure it
     991             :      * won't change underneath us.
     992             :      */
     993         790 :     if (!dbtemplate)
     994         438 :         dbtemplate = "template1"; /* Default template database name */
     995             : 
     996         790 :     if (!get_db_info(dbtemplate, ShareLock,
     997             :                      &src_dboid, &src_owner, &src_encoding,
     998             :                      &src_istemplate, &src_allowconn, &src_hasloginevt,
     999             :                      &src_frozenxid, &src_minmxid, &src_deftablespace,
    1000             :                      &src_collate, &src_ctype, &src_locale, &src_icurules, &src_locprovider,
    1001             :                      &src_collversion))
    1002           0 :         ereport(ERROR,
    1003             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    1004             :                  errmsg("template database \"%s\" does not exist",
    1005             :                         dbtemplate)));
    1006             : 
    1007             :     /*
    1008             :      * If the source database was in the process of being dropped, we can't
    1009             :      * use it as a template.
    1010             :      */
    1011         790 :     if (database_is_invalid_oid(src_dboid))
    1012           2 :         ereport(ERROR,
    1013             :                 errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
    1014             :                 errmsg("cannot use invalid database \"%s\" as template", dbtemplate),
    1015             :                 errhint("Use DROP DATABASE to drop invalid databases."));
    1016             : 
    1017             :     /*
    1018             :      * Permission check: to copy a DB that's not marked datistemplate, you
    1019             :      * must be superuser or the owner thereof.
    1020             :      */
    1021         788 :     if (!src_istemplate)
    1022             :     {
    1023          24 :         if (!object_ownercheck(DatabaseRelationId, src_dboid, GetUserId()))
    1024           0 :             ereport(ERROR,
    1025             :                     (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    1026             :                      errmsg("permission denied to copy database \"%s\"",
    1027             :                             dbtemplate)));
    1028             :     }
    1029             : 
    1030             :     /* Validate the database creation strategy. */
    1031         788 :     if (strategyEl && strategyEl->arg)
    1032             :     {
    1033             :         char       *strategy;
    1034             : 
    1035         292 :         strategy = defGetString(strategyEl);
    1036         292 :         if (pg_strcasecmp(strategy, "wal_log") == 0)
    1037          22 :             dbstrategy = CREATEDB_WAL_LOG;
    1038         270 :         else if (pg_strcasecmp(strategy, "file_copy") == 0)
    1039         268 :             dbstrategy = CREATEDB_FILE_COPY;
    1040             :         else
    1041           2 :             ereport(ERROR,
    1042             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1043             :                      errmsg("invalid create database strategy \"%s\"", strategy),
    1044             :                      errhint("Valid strategies are \"wal_log\" and \"file_copy\".")));
    1045             :     }
    1046             : 
    1047             :     /* If encoding or locales are defaulted, use source's setting */
    1048         786 :     if (encoding < 0)
    1049         682 :         encoding = src_encoding;
    1050         786 :     if (dbcollate == NULL)
    1051         668 :         dbcollate = src_collate;
    1052         786 :     if (dbctype == NULL)
    1053         668 :         dbctype = src_ctype;
    1054         786 :     if (dblocprovider == '\0')
    1055         672 :         dblocprovider = src_locprovider;
    1056         786 :     if (dblocale == NULL && dblocprovider == src_locprovider)
    1057         664 :         dblocale = src_locale;
    1058         786 :     if (dbicurules == NULL)
    1059         784 :         dbicurules = src_icurules;
    1060             : 
    1061             :     /* Some encodings are client only */
    1062         786 :     if (!PG_VALID_BE_ENCODING(encoding))
    1063           0 :         ereport(ERROR,
    1064             :                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1065             :                  errmsg("invalid server encoding %d", encoding)));
    1066             : 
    1067             :     /* Check that the chosen locales are valid, and get canonical spellings */
    1068         786 :     if (!check_locale(LC_COLLATE, dbcollate, &canonname))
    1069             :     {
    1070           2 :         if (dblocprovider == COLLPROVIDER_BUILTIN)
    1071           0 :             ereport(ERROR,
    1072             :                     (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1073             :                      errmsg("invalid LC_COLLATE locale name: \"%s\"", dbcollate),
    1074             :                      errhint("If the locale name is specific to the builtin provider, use BUILTIN_LOCALE.")));
    1075           2 :         else if (dblocprovider == COLLPROVIDER_ICU)
    1076           0 :             ereport(ERROR,
    1077             :                     (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1078             :                      errmsg("invalid LC_COLLATE locale name: \"%s\"", dbcollate),
    1079             :                      errhint("If the locale name is specific to the ICU provider, use ICU_LOCALE.")));
    1080             :         else
    1081           2 :             ereport(ERROR,
    1082             :                     (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1083             :                      errmsg("invalid LC_COLLATE locale name: \"%s\"", dbcollate)));
    1084             :     }
    1085         784 :     dbcollate = canonname;
    1086         784 :     if (!check_locale(LC_CTYPE, dbctype, &canonname))
    1087             :     {
    1088           2 :         if (dblocprovider == COLLPROVIDER_BUILTIN)
    1089           0 :             ereport(ERROR,
    1090             :                     (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1091             :                      errmsg("invalid LC_CTYPE locale name: \"%s\"", dbctype),
    1092             :                      errhint("If the locale name is specific to the builtin provider, use BUILTIN_LOCALE.")));
    1093           2 :         else if (dblocprovider == COLLPROVIDER_ICU)
    1094           0 :             ereport(ERROR,
    1095             :                     (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1096             :                      errmsg("invalid LC_CTYPE locale name: \"%s\"", dbctype),
    1097             :                      errhint("If the locale name is specific to the ICU provider, use ICU_LOCALE.")));
    1098             :         else
    1099           2 :             ereport(ERROR,
    1100             :                     (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1101             :                      errmsg("invalid LC_CTYPE locale name: \"%s\"", dbctype)));
    1102             :     }
    1103             : 
    1104         782 :     dbctype = canonname;
    1105             : 
    1106         782 :     check_encoding_locale_matches(encoding, dbcollate, dbctype);
    1107             : 
    1108             :     /* validate provider-specific parameters */
    1109         782 :     if (dblocprovider != COLLPROVIDER_BUILTIN)
    1110             :     {
    1111         720 :         if (builtinlocaleEl)
    1112           0 :             ereport(ERROR,
    1113             :                     (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
    1114             :                      errmsg("BUILTIN_LOCALE cannot be specified unless locale provider is builtin")));
    1115             :     }
    1116             : 
    1117         782 :     if (dblocprovider != COLLPROVIDER_ICU)
    1118             :     {
    1119         752 :         if (iculocaleEl)
    1120           2 :             ereport(ERROR,
    1121             :                     (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
    1122             :                      errmsg("ICU locale cannot be specified unless locale provider is ICU")));
    1123             : 
    1124         750 :         if (dbicurules)
    1125           2 :             ereport(ERROR,
    1126             :                     (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
    1127             :                      errmsg("ICU rules cannot be specified unless locale provider is ICU")));
    1128             :     }
    1129             : 
    1130             :     /* validate and canonicalize locale for the provider */
    1131         778 :     if (dblocprovider == COLLPROVIDER_BUILTIN)
    1132             :     {
    1133             :         /*
    1134             :          * This would happen if template0 uses the libc provider but the new
    1135             :          * database uses builtin.
    1136             :          */
    1137          58 :         if (!dblocale)
    1138           2 :             ereport(ERROR,
    1139             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1140             :                      errmsg("LOCALE or BUILTIN_LOCALE must be specified")));
    1141             : 
    1142          56 :         dblocale = builtin_validate_locale(encoding, dblocale);
    1143             :     }
    1144         720 :     else if (dblocprovider == COLLPROVIDER_ICU)
    1145             :     {
    1146          30 :         if (!(is_encoding_supported_by_icu(encoding)))
    1147           2 :             ereport(ERROR,
    1148             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1149             :                      errmsg("encoding \"%s\" is not supported with ICU provider",
    1150             :                             pg_encoding_to_char(encoding))));
    1151             : 
    1152             :         /*
    1153             :          * This would happen if template0 uses the libc provider but the new
    1154             :          * database uses icu.
    1155             :          */
    1156          28 :         if (!dblocale)
    1157           2 :             ereport(ERROR,
    1158             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1159             :                      errmsg("LOCALE or ICU_LOCALE must be specified")));
    1160             : 
    1161             :         /*
    1162             :          * During binary upgrade, or when the locale came from the template
    1163             :          * database, preserve locale string. Otherwise, canonicalize to a
    1164             :          * language tag.
    1165             :          */
    1166          26 :         if (!IsBinaryUpgrade && dblocale != src_locale)
    1167             :         {
    1168          14 :             char       *langtag = icu_language_tag(dblocale,
    1169             :                                                    icu_validation_level);
    1170             : 
    1171          14 :             if (langtag && strcmp(dblocale, langtag) != 0)
    1172             :             {
    1173           6 :                 ereport(NOTICE,
    1174             :                         (errmsg("using standard form \"%s\" for ICU locale \"%s\"",
    1175             :                                 langtag, dblocale)));
    1176             : 
    1177           6 :                 dblocale = langtag;
    1178             :             }
    1179             :         }
    1180             : 
    1181          26 :         icu_validate_locale(dblocale);
    1182             :     }
    1183             : 
    1184             :     /* for libc, locale comes from datcollate and datctype */
    1185         768 :     if (dblocprovider == COLLPROVIDER_LIBC)
    1186         690 :         dblocale = NULL;
    1187             : 
    1188             :     /*
    1189             :      * Check that the new encoding and locale settings match the source
    1190             :      * database.  We insist on this because we simply copy the source data ---
    1191             :      * any non-ASCII data would be wrongly encoded, and any indexes sorted
    1192             :      * according to the source locale would be wrong.
    1193             :      *
    1194             :      * However, we assume that template0 doesn't contain any non-ASCII data
    1195             :      * nor any indexes that depend on collation or ctype, so template0 can be
    1196             :      * used as template for creating a database with any encoding or locale.
    1197             :      */
    1198         768 :     if (strcmp(dbtemplate, "template0") != 0)
    1199             :     {
    1200         464 :         if (encoding != src_encoding)
    1201           0 :             ereport(ERROR,
    1202             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1203             :                      errmsg("new encoding (%s) is incompatible with the encoding of the template database (%s)",
    1204             :                             pg_encoding_to_char(encoding),
    1205             :                             pg_encoding_to_char(src_encoding)),
    1206             :                      errhint("Use the same encoding as in the template database, or use template0 as template.")));
    1207             : 
    1208         464 :         if (strcmp(dbcollate, src_collate) != 0)
    1209           2 :             ereport(ERROR,
    1210             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1211             :                      errmsg("new collation (%s) is incompatible with the collation of the template database (%s)",
    1212             :                             dbcollate, src_collate),
    1213             :                      errhint("Use the same collation as in the template database, or use template0 as template.")));
    1214             : 
    1215         462 :         if (strcmp(dbctype, src_ctype) != 0)
    1216           0 :             ereport(ERROR,
    1217             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1218             :                      errmsg("new LC_CTYPE (%s) is incompatible with the LC_CTYPE of the template database (%s)",
    1219             :                             dbctype, src_ctype),
    1220             :                      errhint("Use the same LC_CTYPE as in the template database, or use template0 as template.")));
    1221             : 
    1222         462 :         if (dblocprovider != src_locprovider)
    1223           0 :             ereport(ERROR,
    1224             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1225             :                      errmsg("new locale provider (%s) does not match locale provider of the template database (%s)",
    1226             :                             collprovider_name(dblocprovider), collprovider_name(src_locprovider)),
    1227             :                      errhint("Use the same locale provider as in the template database, or use template0 as template.")));
    1228             : 
    1229         462 :         if (dblocprovider == COLLPROVIDER_ICU)
    1230             :         {
    1231             :             char       *val1;
    1232             :             char       *val2;
    1233             : 
    1234             :             Assert(dblocale);
    1235             :             Assert(src_locale);
    1236          12 :             if (strcmp(dblocale, src_locale) != 0)
    1237           0 :                 ereport(ERROR,
    1238             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1239             :                          errmsg("new ICU locale (%s) is incompatible with the ICU locale of the template database (%s)",
    1240             :                                 dblocale, src_locale),
    1241             :                          errhint("Use the same ICU locale as in the template database, or use template0 as template.")));
    1242             : 
    1243          12 :             val1 = dbicurules;
    1244          12 :             if (!val1)
    1245          12 :                 val1 = "";
    1246          12 :             val2 = src_icurules;
    1247          12 :             if (!val2)
    1248          12 :                 val2 = "";
    1249          12 :             if (strcmp(val1, val2) != 0)
    1250           0 :                 ereport(ERROR,
    1251             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1252             :                          errmsg("new ICU collation rules (%s) are incompatible with the ICU collation rules of the template database (%s)",
    1253             :                                 val1, val2),
    1254             :                          errhint("Use the same ICU collation rules as in the template database, or use template0 as template.")));
    1255             :         }
    1256             :     }
    1257             : 
    1258             :     /*
    1259             :      * If we got a collation version for the template database, check that it
    1260             :      * matches the actual OS collation version.  Otherwise error; the user
    1261             :      * needs to fix the template database first.  Don't complain if a
    1262             :      * collation version was specified explicitly as a statement option; that
    1263             :      * is used by pg_upgrade to reproduce the old state exactly.
    1264             :      *
    1265             :      * (If the template database has no collation version, then either the
    1266             :      * platform/provider does not support collation versioning, or it's
    1267             :      * template0, for which we stipulate that it does not contain
    1268             :      * collation-using objects.)
    1269             :      */
    1270         766 :     if (src_collversion && !collversionEl)
    1271             :     {
    1272             :         char       *actual_versionstr;
    1273             :         const char *locale;
    1274             : 
    1275         304 :         if (dblocprovider == COLLPROVIDER_LIBC)
    1276         282 :             locale = dbcollate;
    1277             :         else
    1278          22 :             locale = dblocale;
    1279             : 
    1280         304 :         actual_versionstr = get_collation_actual_version(dblocprovider, locale);
    1281         304 :         if (!actual_versionstr)
    1282           0 :             ereport(ERROR,
    1283             :                     (errmsg("template database \"%s\" has a collation version, but no actual collation version could be determined",
    1284             :                             dbtemplate)));
    1285             : 
    1286         304 :         if (strcmp(actual_versionstr, src_collversion) != 0)
    1287           0 :             ereport(ERROR,
    1288             :                     (errmsg("template database \"%s\" has a collation version mismatch",
    1289             :                             dbtemplate),
    1290             :                      errdetail("The template database was created using collation version %s, "
    1291             :                                "but the operating system provides version %s.",
    1292             :                                src_collversion, actual_versionstr),
    1293             :                      errhint("Rebuild all objects in the template database that use the default collation and run "
    1294             :                              "ALTER DATABASE %s REFRESH COLLATION VERSION, "
    1295             :                              "or build PostgreSQL with the right library version.",
    1296             :                              quote_identifier(dbtemplate))));
    1297             :     }
    1298             : 
    1299         766 :     if (dbcollversion == NULL)
    1300         710 :         dbcollversion = src_collversion;
    1301             : 
    1302             :     /*
    1303             :      * Normally, we copy the collation version from the template database.
    1304             :      * This last resort only applies if the template database does not have a
    1305             :      * collation version, which is normally only the case for template0.
    1306             :      */
    1307         766 :     if (dbcollversion == NULL)
    1308             :     {
    1309             :         const char *locale;
    1310             : 
    1311         406 :         if (dblocprovider == COLLPROVIDER_LIBC)
    1312         364 :             locale = dbcollate;
    1313             :         else
    1314          42 :             locale = dblocale;
    1315             : 
    1316         406 :         dbcollversion = get_collation_actual_version(dblocprovider, locale);
    1317             :     }
    1318             : 
    1319             :     /* Resolve default tablespace for new database */
    1320         766 :     if (tablespacenameEl && tablespacenameEl->arg)
    1321          34 :     {
    1322             :         char       *tablespacename;
    1323             :         AclResult   aclresult;
    1324             : 
    1325          34 :         tablespacename = defGetString(tablespacenameEl);
    1326          34 :         dst_deftablespace = get_tablespace_oid(tablespacename, false);
    1327             :         /* check permissions */
    1328          34 :         aclresult = object_aclcheck(TableSpaceRelationId, dst_deftablespace, GetUserId(),
    1329             :                                     ACL_CREATE);
    1330          34 :         if (aclresult != ACLCHECK_OK)
    1331           0 :             aclcheck_error(aclresult, OBJECT_TABLESPACE,
    1332             :                            tablespacename);
    1333             : 
    1334             :         /* pg_global must never be the default tablespace */
    1335          34 :         if (dst_deftablespace == GLOBALTABLESPACE_OID)
    1336           0 :             ereport(ERROR,
    1337             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1338             :                      errmsg("pg_global cannot be used as default tablespace")));
    1339             : 
    1340             :         /*
    1341             :          * If we are trying to change the default tablespace of the template,
    1342             :          * we require that the template not have any files in the new default
    1343             :          * tablespace.  This is necessary because otherwise the copied
    1344             :          * database would contain pg_class rows that refer to its default
    1345             :          * tablespace both explicitly (by OID) and implicitly (as zero), which
    1346             :          * would cause problems.  For example another CREATE DATABASE using
    1347             :          * the copied database as template, and trying to change its default
    1348             :          * tablespace again, would yield outright incorrect results (it would
    1349             :          * improperly move tables to the new default tablespace that should
    1350             :          * stay in the same tablespace).
    1351             :          */
    1352          34 :         if (dst_deftablespace != src_deftablespace)
    1353             :         {
    1354             :             char       *srcpath;
    1355             :             struct stat st;
    1356             : 
    1357          34 :             srcpath = GetDatabasePath(src_dboid, dst_deftablespace);
    1358             : 
    1359          34 :             if (stat(srcpath, &st) == 0 &&
    1360           0 :                 S_ISDIR(st.st_mode) &&
    1361           0 :                 !directory_is_empty(srcpath))
    1362           0 :                 ereport(ERROR,
    1363             :                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    1364             :                          errmsg("cannot assign new default tablespace \"%s\"",
    1365             :                                 tablespacename),
    1366             :                          errdetail("There is a conflict because database \"%s\" already has some tables in this tablespace.",
    1367             :                                    dbtemplate)));
    1368          34 :             pfree(srcpath);
    1369             :         }
    1370             :     }
    1371             :     else
    1372             :     {
    1373             :         /* Use template database's default tablespace */
    1374         732 :         dst_deftablespace = src_deftablespace;
    1375             :         /* Note there is no additional permission check in this path */
    1376             :     }
    1377             : 
    1378             :     /*
    1379             :      * If built with appropriate switch, whine when regression-testing
    1380             :      * conventions for database names are violated.  But don't complain during
    1381             :      * initdb.
    1382             :      */
    1383             : #ifdef ENFORCE_REGRESSION_TEST_NAME_RESTRICTIONS
    1384             :     if (IsUnderPostmaster && strstr(dbname, "regression") == NULL)
    1385             :         elog(WARNING, "databases created by regression test cases should have names including \"regression\"");
    1386             : #endif
    1387             : 
    1388             :     /*
    1389             :      * Check for db name conflict.  This is just to give a more friendly error
    1390             :      * message than "unique index violation".  There's a race condition but
    1391             :      * we're willing to accept the less friendly message in that case.
    1392             :      */
    1393         766 :     if (OidIsValid(get_database_oid(dbname, true)))
    1394           2 :         ereport(ERROR,
    1395             :                 (errcode(ERRCODE_DUPLICATE_DATABASE),
    1396             :                  errmsg("database \"%s\" already exists", dbname)));
    1397             : 
    1398             :     /*
    1399             :      * The source DB can't have any active backends, except this one
    1400             :      * (exception is to allow CREATE DB while connected to template1).
    1401             :      * Otherwise we might copy inconsistent data.
    1402             :      *
    1403             :      * This should be last among the basic error checks, because it involves
    1404             :      * potential waiting; we may as well throw an error first if we're gonna
    1405             :      * throw one.
    1406             :      */
    1407         764 :     if (CountOtherDBBackends(src_dboid, &notherbackends, &npreparedxacts))
    1408           0 :         ereport(ERROR,
    1409             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1410             :                  errmsg("source database \"%s\" is being accessed by other users",
    1411             :                         dbtemplate),
    1412             :                  errdetail_busy_db(notherbackends, npreparedxacts)));
    1413             : 
    1414             :     /*
    1415             :      * Select an OID for the new database, checking that it doesn't have a
    1416             :      * filename conflict with anything already existing in the tablespace
    1417             :      * directories.
    1418             :      */
    1419         764 :     pg_database_rel = table_open(DatabaseRelationId, RowExclusiveLock);
    1420             : 
    1421             :     /*
    1422             :      * If database OID is configured, check if the OID is already in use or
    1423             :      * data directory already exists.
    1424             :      */
    1425         764 :     if (OidIsValid(dboid))
    1426             :     {
    1427         258 :         char       *existing_dbname = get_database_name(dboid);
    1428             : 
    1429         258 :         if (existing_dbname != NULL)
    1430           0 :             ereport(ERROR,
    1431             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE)),
    1432             :                     errmsg("database OID %u is already in use by database \"%s\"",
    1433             :                            dboid, existing_dbname));
    1434             : 
    1435         258 :         if (check_db_file_conflict(dboid))
    1436           0 :             ereport(ERROR,
    1437             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE)),
    1438             :                     errmsg("data directory with the specified OID %u already exists", dboid));
    1439             :     }
    1440             :     else
    1441             :     {
    1442             :         /* Select an OID for the new database if is not explicitly configured. */
    1443             :         do
    1444             :         {
    1445         506 :             dboid = GetNewOidWithIndex(pg_database_rel, DatabaseOidIndexId,
    1446             :                                        Anum_pg_database_oid);
    1447         506 :         } while (check_db_file_conflict(dboid));
    1448             :     }
    1449             : 
    1450             :     /*
    1451             :      * Insert a new tuple into pg_database.  This establishes our ownership of
    1452             :      * the new database name (anyone else trying to insert the same name will
    1453             :      * block on the unique index, and fail after we commit).
    1454             :      */
    1455             : 
    1456             :     Assert((dblocprovider != COLLPROVIDER_LIBC && dblocale) ||
    1457             :            (dblocprovider == COLLPROVIDER_LIBC && !dblocale));
    1458             : 
    1459             :     /* Form tuple */
    1460         764 :     new_record[Anum_pg_database_oid - 1] = ObjectIdGetDatum(dboid);
    1461         764 :     new_record[Anum_pg_database_datname - 1] =
    1462         764 :         DirectFunctionCall1(namein, CStringGetDatum(dbname));
    1463         764 :     new_record[Anum_pg_database_datdba - 1] = ObjectIdGetDatum(datdba);
    1464         764 :     new_record[Anum_pg_database_encoding - 1] = Int32GetDatum(encoding);
    1465         764 :     new_record[Anum_pg_database_datlocprovider - 1] = CharGetDatum(dblocprovider);
    1466         764 :     new_record[Anum_pg_database_datistemplate - 1] = BoolGetDatum(dbistemplate);
    1467         764 :     new_record[Anum_pg_database_datallowconn - 1] = BoolGetDatum(dballowconnections);
    1468         764 :     new_record[Anum_pg_database_dathasloginevt - 1] = BoolGetDatum(src_hasloginevt);
    1469         764 :     new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(dbconnlimit);
    1470         764 :     new_record[Anum_pg_database_datfrozenxid - 1] = TransactionIdGetDatum(src_frozenxid);
    1471         764 :     new_record[Anum_pg_database_datminmxid - 1] = TransactionIdGetDatum(src_minmxid);
    1472         764 :     new_record[Anum_pg_database_dattablespace - 1] = ObjectIdGetDatum(dst_deftablespace);
    1473         764 :     new_record[Anum_pg_database_datcollate - 1] = CStringGetTextDatum(dbcollate);
    1474         764 :     new_record[Anum_pg_database_datctype - 1] = CStringGetTextDatum(dbctype);
    1475         764 :     if (dblocale)
    1476          76 :         new_record[Anum_pg_database_datlocale - 1] = CStringGetTextDatum(dblocale);
    1477             :     else
    1478         688 :         new_record_nulls[Anum_pg_database_datlocale - 1] = true;
    1479         764 :     if (dbicurules)
    1480           0 :         new_record[Anum_pg_database_daticurules - 1] = CStringGetTextDatum(dbicurules);
    1481             :     else
    1482         764 :         new_record_nulls[Anum_pg_database_daticurules - 1] = true;
    1483         764 :     if (dbcollversion)
    1484         648 :         new_record[Anum_pg_database_datcollversion - 1] = CStringGetTextDatum(dbcollversion);
    1485             :     else
    1486         116 :         new_record_nulls[Anum_pg_database_datcollversion - 1] = true;
    1487             : 
    1488             :     /*
    1489             :      * We deliberately set datacl to default (NULL), rather than copying it
    1490             :      * from the template database.  Copying it would be a bad idea when the
    1491             :      * owner is not the same as the template's owner.
    1492             :      */
    1493         764 :     new_record_nulls[Anum_pg_database_datacl - 1] = true;
    1494             : 
    1495         764 :     tuple = heap_form_tuple(RelationGetDescr(pg_database_rel),
    1496             :                             new_record, new_record_nulls);
    1497             : 
    1498         764 :     CatalogTupleInsert(pg_database_rel, tuple);
    1499             : 
    1500             :     /*
    1501             :      * Now generate additional catalog entries associated with the new DB
    1502             :      */
    1503             : 
    1504             :     /* Register owner dependency */
    1505         764 :     recordDependencyOnOwner(DatabaseRelationId, dboid, datdba);
    1506             : 
    1507             :     /* Create pg_shdepend entries for objects within database */
    1508         764 :     copyTemplateDependencies(src_dboid, dboid);
    1509             : 
    1510             :     /* Post creation hook for new database */
    1511         764 :     InvokeObjectPostCreateHook(DatabaseRelationId, dboid, 0);
    1512             : 
    1513             :     /*
    1514             :      * If we're going to be reading data for the to-be-created database into
    1515             :      * shared_buffers, take a lock on it. Nobody should know that this
    1516             :      * database exists yet, but it's good to maintain the invariant that an
    1517             :      * AccessExclusiveLock on the database is sufficient to drop all of its
    1518             :      * buffers without worrying about more being read later.
    1519             :      *
    1520             :      * Note that we need to do this before entering the
    1521             :      * PG_ENSURE_ERROR_CLEANUP block below, because createdb_failure_callback
    1522             :      * expects this lock to be held already.
    1523             :      */
    1524         764 :     if (dbstrategy == CREATEDB_WAL_LOG)
    1525         496 :         LockSharedObject(DatabaseRelationId, dboid, 0, AccessShareLock);
    1526             : 
    1527             :     /*
    1528             :      * Once we start copying subdirectories, we need to be able to clean 'em
    1529             :      * up if we fail.  Use an ENSURE block to make sure this happens.  (This
    1530             :      * is not a 100% solution, because of the possibility of failure during
    1531             :      * transaction commit after we leave this routine, but it should handle
    1532             :      * most scenarios.)
    1533             :      */
    1534         764 :     fparms.src_dboid = src_dboid;
    1535         764 :     fparms.dest_dboid = dboid;
    1536         764 :     fparms.strategy = dbstrategy;
    1537             : 
    1538         764 :     PG_ENSURE_ERROR_CLEANUP(createdb_failure_callback,
    1539             :                             PointerGetDatum(&fparms));
    1540             :     {
    1541             :         /*
    1542             :          * If the user has asked to create a database with WAL_LOG strategy
    1543             :          * then call CreateDatabaseUsingWalLog, which will copy the database
    1544             :          * at the block level and it will WAL log each copied block.
    1545             :          * Otherwise, call CreateDatabaseUsingFileCopy that will copy the
    1546             :          * database file by file.
    1547             :          */
    1548         764 :         if (dbstrategy == CREATEDB_WAL_LOG)
    1549         496 :             CreateDatabaseUsingWalLog(src_dboid, dboid, src_deftablespace,
    1550             :                                       dst_deftablespace);
    1551             :         else
    1552         268 :             CreateDatabaseUsingFileCopy(src_dboid, dboid, src_deftablespace,
    1553             :                                         dst_deftablespace);
    1554             : 
    1555             :         /*
    1556             :          * Close pg_database, but keep lock till commit.
    1557             :          */
    1558         760 :         table_close(pg_database_rel, NoLock);
    1559             : 
    1560             :         /*
    1561             :          * Force synchronous commit, thus minimizing the window between
    1562             :          * creation of the database files and committal of the transaction. If
    1563             :          * we crash before committing, we'll have a DB that's taking up disk
    1564             :          * space but is not in pg_database, which is not good.
    1565             :          */
    1566         760 :         ForceSyncCommit();
    1567             :     }
    1568         764 :     PG_END_ENSURE_ERROR_CLEANUP(createdb_failure_callback,
    1569             :                                 PointerGetDatum(&fparms));
    1570             : 
    1571         760 :     return dboid;
    1572             : }
    1573             : 
    1574             : /*
    1575             :  * Check whether chosen encoding matches chosen locale settings.  This
    1576             :  * restriction is necessary because libc's locale-specific code usually
    1577             :  * fails when presented with data in an encoding it's not expecting. We
    1578             :  * allow mismatch in four cases:
    1579             :  *
    1580             :  * 1. locale encoding = SQL_ASCII, which means that the locale is C/POSIX
    1581             :  * which works with any encoding.
    1582             :  *
    1583             :  * 2. locale encoding = -1, which means that we couldn't determine the
    1584             :  * locale's encoding and have to trust the user to get it right.
    1585             :  *
    1586             :  * 3. selected encoding is UTF8 and platform is win32. This is because
    1587             :  * UTF8 is a pseudo codepage that is supported in all locales since it's
    1588             :  * converted to UTF16 before being used.
    1589             :  *
    1590             :  * 4. selected encoding is SQL_ASCII, but only if you're a superuser. This
    1591             :  * is risky but we have historically allowed it --- notably, the
    1592             :  * regression tests require it.
    1593             :  *
    1594             :  * Note: if you change this policy, fix initdb to match.
    1595             :  */
    1596             : void
    1597         810 : check_encoding_locale_matches(int encoding, const char *collate, const char *ctype)
    1598             : {
    1599         810 :     int         ctype_encoding = pg_get_encoding_from_locale(ctype, true);
    1600         810 :     int         collate_encoding = pg_get_encoding_from_locale(collate, true);
    1601             : 
    1602         818 :     if (!(ctype_encoding == encoding ||
    1603           8 :           ctype_encoding == PG_SQL_ASCII ||
    1604             :           ctype_encoding == -1 ||
    1605             : #ifdef WIN32
    1606             :           encoding == PG_UTF8 ||
    1607             : #endif
    1608           8 :           (encoding == PG_SQL_ASCII && superuser())))
    1609           0 :         ereport(ERROR,
    1610             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1611             :                  errmsg("encoding \"%s\" does not match locale \"%s\"",
    1612             :                         pg_encoding_to_char(encoding),
    1613             :                         ctype),
    1614             :                  errdetail("The chosen LC_CTYPE setting requires encoding \"%s\".",
    1615             :                            pg_encoding_to_char(ctype_encoding))));
    1616             : 
    1617         818 :     if (!(collate_encoding == encoding ||
    1618           8 :           collate_encoding == PG_SQL_ASCII ||
    1619             :           collate_encoding == -1 ||
    1620             : #ifdef WIN32
    1621             :           encoding == PG_UTF8 ||
    1622             : #endif
    1623           8 :           (encoding == PG_SQL_ASCII && superuser())))
    1624           0 :         ereport(ERROR,
    1625             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1626             :                  errmsg("encoding \"%s\" does not match locale \"%s\"",
    1627             :                         pg_encoding_to_char(encoding),
    1628             :                         collate),
    1629             :                  errdetail("The chosen LC_COLLATE setting requires encoding \"%s\".",
    1630             :                            pg_encoding_to_char(collate_encoding))));
    1631         810 : }
    1632             : 
    1633             : /* Error cleanup callback for createdb */
    1634             : static void
    1635           4 : createdb_failure_callback(int code, Datum arg)
    1636             : {
    1637           4 :     createdb_failure_params *fparms = (createdb_failure_params *) DatumGetPointer(arg);
    1638             : 
    1639             :     /*
    1640             :      * If we were copying database at block levels then drop pages for the
    1641             :      * destination database that are in the shared buffer cache.  And tell
    1642             :      * checkpointer to forget any pending fsync and unlink requests for files
    1643             :      * in the database.  The reasoning behind doing this is same as explained
    1644             :      * in dropdb function.  But unlike dropdb we don't need to call
    1645             :      * pgstat_drop_database because this database is still not created so
    1646             :      * there should not be any stat for this.
    1647             :      */
    1648           4 :     if (fparms->strategy == CREATEDB_WAL_LOG)
    1649             :     {
    1650           4 :         DropDatabaseBuffers(fparms->dest_dboid);
    1651           4 :         ForgetDatabaseSyncRequests(fparms->dest_dboid);
    1652             : 
    1653             :         /* Release lock on the target database. */
    1654           4 :         UnlockSharedObject(DatabaseRelationId, fparms->dest_dboid, 0,
    1655             :                            AccessShareLock);
    1656             :     }
    1657             : 
    1658             :     /*
    1659             :      * Release lock on source database before doing recursive remove. This is
    1660             :      * not essential but it seems desirable to release the lock as soon as
    1661             :      * possible.
    1662             :      */
    1663           4 :     UnlockSharedObject(DatabaseRelationId, fparms->src_dboid, 0, ShareLock);
    1664             : 
    1665             :     /* Throw away any successfully copied subdirectories */
    1666           4 :     remove_dbtablespaces(fparms->dest_dboid);
    1667           4 : }
    1668             : 
    1669             : 
    1670             : /*
    1671             :  * DROP DATABASE
    1672             :  */
    1673             : void
    1674         124 : dropdb(const char *dbname, bool missing_ok, bool force)
    1675             : {
    1676             :     Oid         db_id;
    1677             :     bool        db_istemplate;
    1678             :     Relation    pgdbrel;
    1679             :     HeapTuple   tup;
    1680             :     ScanKeyData scankey;
    1681             :     void       *inplace_state;
    1682             :     Form_pg_database datform;
    1683             :     int         notherbackends;
    1684             :     int         npreparedxacts;
    1685             :     int         nslots,
    1686             :                 nslots_active;
    1687             :     int         nsubscriptions;
    1688             : 
    1689             :     /*
    1690             :      * Look up the target database's OID, and get exclusive lock on it. We
    1691             :      * need this to ensure that no new backend starts up in the target
    1692             :      * database while we are deleting it (see postinit.c), and that no one is
    1693             :      * using it as a CREATE DATABASE template or trying to delete it for
    1694             :      * themselves.
    1695             :      */
    1696         124 :     pgdbrel = table_open(DatabaseRelationId, RowExclusiveLock);
    1697             : 
    1698         124 :     if (!get_db_info(dbname, AccessExclusiveLock, &db_id, NULL, NULL,
    1699             :                      &db_istemplate, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL))
    1700             :     {
    1701          32 :         if (!missing_ok)
    1702             :         {
    1703          16 :             ereport(ERROR,
    1704             :                     (errcode(ERRCODE_UNDEFINED_DATABASE),
    1705             :                      errmsg("database \"%s\" does not exist", dbname)));
    1706             :         }
    1707             :         else
    1708             :         {
    1709             :             /* Close pg_database, release the lock, since we changed nothing */
    1710          16 :             table_close(pgdbrel, RowExclusiveLock);
    1711          16 :             ereport(NOTICE,
    1712             :                     (errmsg("database \"%s\" does not exist, skipping",
    1713             :                             dbname)));
    1714          16 :             return;
    1715             :         }
    1716             :     }
    1717             : 
    1718             :     /*
    1719             :      * Permission checks
    1720             :      */
    1721          92 :     if (!object_ownercheck(DatabaseRelationId, db_id, GetUserId()))
    1722           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    1723             :                        dbname);
    1724             : 
    1725             :     /* DROP hook for the database being removed */
    1726          92 :     InvokeObjectDropHook(DatabaseRelationId, db_id, 0);
    1727             : 
    1728             :     /*
    1729             :      * Disallow dropping a DB that is marked istemplate.  This is just to
    1730             :      * prevent people from accidentally dropping template0 or template1; they
    1731             :      * can do so if they're really determined ...
    1732             :      */
    1733          92 :     if (db_istemplate)
    1734           0 :         ereport(ERROR,
    1735             :                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1736             :                  errmsg("cannot drop a template database")));
    1737             : 
    1738             :     /* Obviously can't drop my own database */
    1739          92 :     if (db_id == MyDatabaseId)
    1740           0 :         ereport(ERROR,
    1741             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1742             :                  errmsg("cannot drop the currently open database")));
    1743             : 
    1744             :     /*
    1745             :      * Check whether there are active logical slots that refer to the
    1746             :      * to-be-dropped database. The database lock we are holding prevents the
    1747             :      * creation of new slots using the database or existing slots becoming
    1748             :      * active.
    1749             :      */
    1750          92 :     (void) ReplicationSlotsCountDBSlots(db_id, &nslots, &nslots_active);
    1751          92 :     if (nslots_active)
    1752             :     {
    1753           2 :         ereport(ERROR,
    1754             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1755             :                  errmsg("database \"%s\" is used by an active logical replication slot",
    1756             :                         dbname),
    1757             :                  errdetail_plural("There is %d active slot.",
    1758             :                                   "There are %d active slots.",
    1759             :                                   nslots_active, nslots_active)));
    1760             :     }
    1761             : 
    1762             :     /*
    1763             :      * Check if there are subscriptions defined in the target database.
    1764             :      *
    1765             :      * We can't drop them automatically because they might be holding
    1766             :      * resources in other databases/instances.
    1767             :      */
    1768          90 :     if ((nsubscriptions = CountDBSubscriptions(db_id)) > 0)
    1769           0 :         ereport(ERROR,
    1770             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1771             :                  errmsg("database \"%s\" is being used by logical replication subscription",
    1772             :                         dbname),
    1773             :                  errdetail_plural("There is %d subscription.",
    1774             :                                   "There are %d subscriptions.",
    1775             :                                   nsubscriptions, nsubscriptions)));
    1776             : 
    1777             : 
    1778             :     /*
    1779             :      * Attempt to terminate all existing connections to the target database if
    1780             :      * the user has requested to do so.
    1781             :      */
    1782          90 :     if (force)
    1783           2 :         TerminateOtherDBBackends(db_id);
    1784             : 
    1785             :     /*
    1786             :      * Check for other backends in the target database.  (Because we hold the
    1787             :      * database lock, no new ones can start after this.)
    1788             :      *
    1789             :      * As in CREATE DATABASE, check this after other error conditions.
    1790             :      */
    1791          90 :     if (CountOtherDBBackends(db_id, &notherbackends, &npreparedxacts))
    1792           0 :         ereport(ERROR,
    1793             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1794             :                  errmsg("database \"%s\" is being accessed by other users",
    1795             :                         dbname),
    1796             :                  errdetail_busy_db(notherbackends, npreparedxacts)));
    1797             : 
    1798             :     /*
    1799             :      * Delete any comments or security labels associated with the database.
    1800             :      */
    1801          90 :     DeleteSharedComments(db_id, DatabaseRelationId);
    1802          90 :     DeleteSharedSecurityLabel(db_id, DatabaseRelationId);
    1803             : 
    1804             :     /*
    1805             :      * Remove settings associated with this database
    1806             :      */
    1807          90 :     DropSetting(db_id, InvalidOid);
    1808             : 
    1809             :     /*
    1810             :      * Remove shared dependency references for the database.
    1811             :      */
    1812          90 :     dropDatabaseDependencies(db_id);
    1813             : 
    1814             :     /*
    1815             :      * Tell the cumulative stats system to forget it immediately, too.
    1816             :      */
    1817          90 :     pgstat_drop_database(db_id);
    1818             : 
    1819             :     /*
    1820             :      * Except for the deletion of the catalog row, subsequent actions are not
    1821             :      * transactional (consider DropDatabaseBuffers() discarding modified
    1822             :      * buffers). But we might crash or get interrupted below. To prevent
    1823             :      * accesses to a database with invalid contents, mark the database as
    1824             :      * invalid using an in-place update.
    1825             :      *
    1826             :      * We need to flush the WAL before continuing, to guarantee the
    1827             :      * modification is durable before performing irreversible filesystem
    1828             :      * operations.
    1829             :      */
    1830          90 :     ScanKeyInit(&scankey,
    1831             :                 Anum_pg_database_datname,
    1832             :                 BTEqualStrategyNumber, F_NAMEEQ,
    1833             :                 CStringGetDatum(dbname));
    1834          90 :     systable_inplace_update_begin(pgdbrel, DatabaseNameIndexId, true,
    1835             :                                   NULL, 1, &scankey, &tup, &inplace_state);
    1836          90 :     if (!HeapTupleIsValid(tup))
    1837           0 :         elog(ERROR, "cache lookup failed for database %u", db_id);
    1838          90 :     datform = (Form_pg_database) GETSTRUCT(tup);
    1839          90 :     datform->datconnlimit = DATCONNLIMIT_INVALID_DB;
    1840          90 :     systable_inplace_update_finish(inplace_state, tup);
    1841          90 :     XLogFlush(XactLastRecEnd);
    1842             : 
    1843             :     /*
    1844             :      * Also delete the tuple - transactionally. If this transaction commits,
    1845             :      * the row will be gone, but if we fail, dropdb() can be invoked again.
    1846             :      */
    1847          90 :     CatalogTupleDelete(pgdbrel, &tup->t_self);
    1848          90 :     heap_freetuple(tup);
    1849             : 
    1850             :     /*
    1851             :      * Drop db-specific replication slots.
    1852             :      */
    1853          90 :     ReplicationSlotsDropDBSlots(db_id);
    1854             : 
    1855             :     /*
    1856             :      * Drop pages for this database that are in the shared buffer cache. This
    1857             :      * is important to ensure that no remaining backend tries to write out a
    1858             :      * dirty buffer to the dead database later...
    1859             :      */
    1860          90 :     DropDatabaseBuffers(db_id);
    1861             : 
    1862             :     /*
    1863             :      * Tell checkpointer to forget any pending fsync and unlink requests for
    1864             :      * files in the database; else the fsyncs will fail at next checkpoint, or
    1865             :      * worse, it will delete files that belong to a newly created database
    1866             :      * with the same OID.
    1867             :      */
    1868          90 :     ForgetDatabaseSyncRequests(db_id);
    1869             : 
    1870             :     /*
    1871             :      * Force a checkpoint to make sure the checkpointer has received the
    1872             :      * message sent by ForgetDatabaseSyncRequests.
    1873             :      */
    1874          90 :     RequestCheckpoint(CHECKPOINT_FAST | CHECKPOINT_FORCE | CHECKPOINT_WAIT);
    1875             : 
    1876             :     /* Close all smgr fds in all backends. */
    1877          90 :     WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_SMGRRELEASE));
    1878             : 
    1879             :     /*
    1880             :      * Remove all tablespace subdirs belonging to the database.
    1881             :      */
    1882          90 :     remove_dbtablespaces(db_id);
    1883             : 
    1884             :     /*
    1885             :      * Close pg_database, but keep lock till commit.
    1886             :      */
    1887          90 :     table_close(pgdbrel, NoLock);
    1888             : 
    1889             :     /*
    1890             :      * Force synchronous commit, thus minimizing the window between removal of
    1891             :      * the database files and committal of the transaction. If we crash before
    1892             :      * committing, we'll have a DB that's gone on disk but still there
    1893             :      * according to pg_database, which is not good.
    1894             :      */
    1895          90 :     ForceSyncCommit();
    1896             : }
    1897             : 
    1898             : 
    1899             : /*
    1900             :  * Rename database
    1901             :  */
    1902             : ObjectAddress
    1903          12 : RenameDatabase(const char *oldname, const char *newname)
    1904             : {
    1905             :     Oid         db_id;
    1906             :     HeapTuple   newtup;
    1907             :     ItemPointerData otid;
    1908             :     Relation    rel;
    1909             :     int         notherbackends;
    1910             :     int         npreparedxacts;
    1911             :     ObjectAddress address;
    1912             : 
    1913             :     /*
    1914             :      * Look up the target database's OID, and get exclusive lock on it. We
    1915             :      * need this for the same reasons as DROP DATABASE.
    1916             :      */
    1917          12 :     rel = table_open(DatabaseRelationId, RowExclusiveLock);
    1918             : 
    1919          12 :     if (!get_db_info(oldname, AccessExclusiveLock, &db_id, NULL, NULL, NULL,
    1920             :                      NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL))
    1921           0 :         ereport(ERROR,
    1922             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    1923             :                  errmsg("database \"%s\" does not exist", oldname)));
    1924             : 
    1925             :     /* must be owner */
    1926          12 :     if (!object_ownercheck(DatabaseRelationId, db_id, GetUserId()))
    1927           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    1928             :                        oldname);
    1929             : 
    1930             :     /* must have createdb rights */
    1931          12 :     if (!have_createdb_privilege())
    1932           0 :         ereport(ERROR,
    1933             :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    1934             :                  errmsg("permission denied to rename database")));
    1935             : 
    1936             :     /*
    1937             :      * If built with appropriate switch, whine when regression-testing
    1938             :      * conventions for database names are violated.
    1939             :      */
    1940             : #ifdef ENFORCE_REGRESSION_TEST_NAME_RESTRICTIONS
    1941             :     if (strstr(newname, "regression") == NULL)
    1942             :         elog(WARNING, "databases created by regression test cases should have names including \"regression\"");
    1943             : #endif
    1944             : 
    1945             :     /*
    1946             :      * Make sure the new name doesn't exist.  See notes for same error in
    1947             :      * CREATE DATABASE.
    1948             :      */
    1949          12 :     if (OidIsValid(get_database_oid(newname, true)))
    1950           0 :         ereport(ERROR,
    1951             :                 (errcode(ERRCODE_DUPLICATE_DATABASE),
    1952             :                  errmsg("database \"%s\" already exists", newname)));
    1953             : 
    1954             :     /*
    1955             :      * XXX Client applications probably store the current database somewhere,
    1956             :      * so renaming it could cause confusion.  On the other hand, there may not
    1957             :      * be an actual problem besides a little confusion, so think about this
    1958             :      * and decide.
    1959             :      */
    1960          12 :     if (db_id == MyDatabaseId)
    1961           0 :         ereport(ERROR,
    1962             :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    1963             :                  errmsg("current database cannot be renamed")));
    1964             : 
    1965             :     /*
    1966             :      * Make sure the database does not have active sessions.  This is the same
    1967             :      * concern as above, but applied to other sessions.
    1968             :      *
    1969             :      * As in CREATE DATABASE, check this after other error conditions.
    1970             :      */
    1971          12 :     if (CountOtherDBBackends(db_id, &notherbackends, &npreparedxacts))
    1972           0 :         ereport(ERROR,
    1973             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1974             :                  errmsg("database \"%s\" is being accessed by other users",
    1975             :                         oldname),
    1976             :                  errdetail_busy_db(notherbackends, npreparedxacts)));
    1977             : 
    1978             :     /* rename */
    1979          12 :     newtup = SearchSysCacheLockedCopy1(DATABASEOID, ObjectIdGetDatum(db_id));
    1980          12 :     if (!HeapTupleIsValid(newtup))
    1981           0 :         elog(ERROR, "cache lookup failed for database %u", db_id);
    1982          12 :     otid = newtup->t_self;
    1983          12 :     namestrcpy(&(((Form_pg_database) GETSTRUCT(newtup))->datname), newname);
    1984          12 :     CatalogTupleUpdate(rel, &otid, newtup);
    1985          12 :     UnlockTuple(rel, &otid, InplaceUpdateTupleLock);
    1986             : 
    1987          12 :     InvokeObjectPostAlterHook(DatabaseRelationId, db_id, 0);
    1988             : 
    1989          12 :     ObjectAddressSet(address, DatabaseRelationId, db_id);
    1990             : 
    1991             :     /*
    1992             :      * Close pg_database, but keep lock till commit.
    1993             :      */
    1994          12 :     table_close(rel, NoLock);
    1995             : 
    1996          12 :     return address;
    1997             : }
    1998             : 
    1999             : 
    2000             : /*
    2001             :  * ALTER DATABASE SET TABLESPACE
    2002             :  */
    2003             : static void
    2004          22 : movedb(const char *dbname, const char *tblspcname)
    2005             : {
    2006             :     Oid         db_id;
    2007             :     Relation    pgdbrel;
    2008             :     int         notherbackends;
    2009             :     int         npreparedxacts;
    2010             :     HeapTuple   oldtuple,
    2011             :                 newtuple;
    2012             :     Oid         src_tblspcoid,
    2013             :                 dst_tblspcoid;
    2014             :     ScanKeyData scankey;
    2015             :     SysScanDesc sysscan;
    2016             :     AclResult   aclresult;
    2017             :     char       *src_dbpath;
    2018             :     char       *dst_dbpath;
    2019             :     DIR        *dstdir;
    2020             :     struct dirent *xlde;
    2021             :     movedb_failure_params fparms;
    2022             : 
    2023             :     /*
    2024             :      * Look up the target database's OID, and get exclusive lock on it. We
    2025             :      * need this to ensure that no new backend starts up in the database while
    2026             :      * we are moving it, and that no one is using it as a CREATE DATABASE
    2027             :      * template or trying to delete it.
    2028             :      */
    2029          22 :     pgdbrel = table_open(DatabaseRelationId, RowExclusiveLock);
    2030             : 
    2031          22 :     if (!get_db_info(dbname, AccessExclusiveLock, &db_id, NULL, NULL, NULL,
    2032             :                      NULL, NULL, NULL, NULL, &src_tblspcoid, NULL, NULL, NULL, NULL, NULL, NULL))
    2033           0 :         ereport(ERROR,
    2034             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    2035             :                  errmsg("database \"%s\" does not exist", dbname)));
    2036             : 
    2037             :     /*
    2038             :      * We actually need a session lock, so that the lock will persist across
    2039             :      * the commit/restart below.  (We could almost get away with letting the
    2040             :      * lock be released at commit, except that someone could try to move
    2041             :      * relations of the DB back into the old directory while we rmtree() it.)
    2042             :      */
    2043          22 :     LockSharedObjectForSession(DatabaseRelationId, db_id, 0,
    2044             :                                AccessExclusiveLock);
    2045             : 
    2046             :     /*
    2047             :      * Permission checks
    2048             :      */
    2049          22 :     if (!object_ownercheck(DatabaseRelationId, db_id, GetUserId()))
    2050           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    2051             :                        dbname);
    2052             : 
    2053             :     /*
    2054             :      * Obviously can't move the tables of my own database
    2055             :      */
    2056          22 :     if (db_id == MyDatabaseId)
    2057           0 :         ereport(ERROR,
    2058             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    2059             :                  errmsg("cannot change the tablespace of the currently open database")));
    2060             : 
    2061             :     /*
    2062             :      * Get tablespace's oid
    2063             :      */
    2064          22 :     dst_tblspcoid = get_tablespace_oid(tblspcname, false);
    2065             : 
    2066             :     /*
    2067             :      * Permission checks
    2068             :      */
    2069          22 :     aclresult = object_aclcheck(TableSpaceRelationId, dst_tblspcoid, GetUserId(),
    2070             :                                 ACL_CREATE);
    2071          22 :     if (aclresult != ACLCHECK_OK)
    2072           0 :         aclcheck_error(aclresult, OBJECT_TABLESPACE,
    2073             :                        tblspcname);
    2074             : 
    2075             :     /*
    2076             :      * pg_global must never be the default tablespace
    2077             :      */
    2078          22 :     if (dst_tblspcoid == GLOBALTABLESPACE_OID)
    2079           0 :         ereport(ERROR,
    2080             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    2081             :                  errmsg("pg_global cannot be used as default tablespace")));
    2082             : 
    2083             :     /*
    2084             :      * No-op if same tablespace
    2085             :      */
    2086          22 :     if (src_tblspcoid == dst_tblspcoid)
    2087             :     {
    2088           0 :         table_close(pgdbrel, NoLock);
    2089           0 :         UnlockSharedObjectForSession(DatabaseRelationId, db_id, 0,
    2090             :                                      AccessExclusiveLock);
    2091           0 :         return;
    2092             :     }
    2093             : 
    2094             :     /*
    2095             :      * Check for other backends in the target database.  (Because we hold the
    2096             :      * database lock, no new ones can start after this.)
    2097             :      *
    2098             :      * As in CREATE DATABASE, check this after other error conditions.
    2099             :      */
    2100          22 :     if (CountOtherDBBackends(db_id, &notherbackends, &npreparedxacts))
    2101           0 :         ereport(ERROR,
    2102             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    2103             :                  errmsg("database \"%s\" is being accessed by other users",
    2104             :                         dbname),
    2105             :                  errdetail_busy_db(notherbackends, npreparedxacts)));
    2106             : 
    2107             :     /*
    2108             :      * Get old and new database paths
    2109             :      */
    2110          22 :     src_dbpath = GetDatabasePath(db_id, src_tblspcoid);
    2111          22 :     dst_dbpath = GetDatabasePath(db_id, dst_tblspcoid);
    2112             : 
    2113             :     /*
    2114             :      * Force a checkpoint before proceeding. This will force all dirty
    2115             :      * buffers, including those of unlogged tables, out to disk, to ensure
    2116             :      * source database is up-to-date on disk for the copy.
    2117             :      * FlushDatabaseBuffers() would suffice for that, but we also want to
    2118             :      * process any pending unlink requests. Otherwise, the check for existing
    2119             :      * files in the target directory might fail unnecessarily, not to mention
    2120             :      * that the copy might fail due to source files getting deleted under it.
    2121             :      * On Windows, this also ensures that background procs don't hold any open
    2122             :      * files, which would cause rmdir() to fail.
    2123             :      */
    2124          22 :     RequestCheckpoint(CHECKPOINT_FAST | CHECKPOINT_FORCE | CHECKPOINT_WAIT
    2125             :                       | CHECKPOINT_FLUSH_UNLOGGED);
    2126             : 
    2127             :     /* Close all smgr fds in all backends. */
    2128          22 :     WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_SMGRRELEASE));
    2129             : 
    2130             :     /*
    2131             :      * Now drop all buffers holding data of the target database; they should
    2132             :      * no longer be dirty so DropDatabaseBuffers is safe.
    2133             :      *
    2134             :      * It might seem that we could just let these buffers age out of shared
    2135             :      * buffers naturally, since they should not get referenced anymore.  The
    2136             :      * problem with that is that if the user later moves the database back to
    2137             :      * its original tablespace, any still-surviving buffers would appear to
    2138             :      * contain valid data again --- but they'd be missing any changes made in
    2139             :      * the database while it was in the new tablespace.  In any case, freeing
    2140             :      * buffers that should never be used again seems worth the cycles.
    2141             :      *
    2142             :      * Note: it'd be sufficient to get rid of buffers matching db_id and
    2143             :      * src_tblspcoid, but bufmgr.c presently provides no API for that.
    2144             :      */
    2145          22 :     DropDatabaseBuffers(db_id);
    2146             : 
    2147             :     /*
    2148             :      * Check for existence of files in the target directory, i.e., objects of
    2149             :      * this database that are already in the target tablespace.  We can't
    2150             :      * allow the move in such a case, because we would need to change those
    2151             :      * relations' pg_class.reltablespace entries to zero, and we don't have
    2152             :      * access to the DB's pg_class to do so.
    2153             :      */
    2154          22 :     dstdir = AllocateDir(dst_dbpath);
    2155          22 :     if (dstdir != NULL)
    2156             :     {
    2157           0 :         while ((xlde = ReadDir(dstdir, dst_dbpath)) != NULL)
    2158             :         {
    2159           0 :             if (strcmp(xlde->d_name, ".") == 0 ||
    2160           0 :                 strcmp(xlde->d_name, "..") == 0)
    2161           0 :                 continue;
    2162             : 
    2163           0 :             ereport(ERROR,
    2164             :                     (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
    2165             :                      errmsg("some relations of database \"%s\" are already in tablespace \"%s\"",
    2166             :                             dbname, tblspcname),
    2167             :                      errhint("You must move them back to the database's default tablespace before using this command.")));
    2168             :         }
    2169             : 
    2170           0 :         FreeDir(dstdir);
    2171             : 
    2172             :         /*
    2173             :          * The directory exists but is empty. We must remove it before using
    2174             :          * the copydir function.
    2175             :          */
    2176           0 :         if (rmdir(dst_dbpath) != 0)
    2177           0 :             elog(ERROR, "could not remove directory \"%s\": %m",
    2178             :                  dst_dbpath);
    2179             :     }
    2180             : 
    2181             :     /*
    2182             :      * Use an ENSURE block to make sure we remove the debris if the copy fails
    2183             :      * (eg, due to out-of-disk-space).  This is not a 100% solution, because
    2184             :      * of the possibility of failure during transaction commit, but it should
    2185             :      * handle most scenarios.
    2186             :      */
    2187          22 :     fparms.dest_dboid = db_id;
    2188          22 :     fparms.dest_tsoid = dst_tblspcoid;
    2189          22 :     PG_ENSURE_ERROR_CLEANUP(movedb_failure_callback,
    2190             :                             PointerGetDatum(&fparms));
    2191             :     {
    2192          22 :         Datum       new_record[Natts_pg_database] = {0};
    2193          22 :         bool        new_record_nulls[Natts_pg_database] = {0};
    2194          22 :         bool        new_record_repl[Natts_pg_database] = {0};
    2195             : 
    2196             :         /*
    2197             :          * Copy files from the old tablespace to the new one
    2198             :          */
    2199          22 :         copydir(src_dbpath, dst_dbpath, false);
    2200             : 
    2201             :         /*
    2202             :          * Record the filesystem change in XLOG
    2203             :          */
    2204             :         {
    2205             :             xl_dbase_create_file_copy_rec xlrec;
    2206             : 
    2207          22 :             xlrec.db_id = db_id;
    2208          22 :             xlrec.tablespace_id = dst_tblspcoid;
    2209          22 :             xlrec.src_db_id = db_id;
    2210          22 :             xlrec.src_tablespace_id = src_tblspcoid;
    2211             : 
    2212          22 :             XLogBeginInsert();
    2213          22 :             XLogRegisterData(&xlrec,
    2214             :                              sizeof(xl_dbase_create_file_copy_rec));
    2215             : 
    2216          22 :             (void) XLogInsert(RM_DBASE_ID,
    2217             :                               XLOG_DBASE_CREATE_FILE_COPY | XLR_SPECIAL_REL_UPDATE);
    2218             :         }
    2219             : 
    2220             :         /*
    2221             :          * Update the database's pg_database tuple
    2222             :          */
    2223          22 :         ScanKeyInit(&scankey,
    2224             :                     Anum_pg_database_datname,
    2225             :                     BTEqualStrategyNumber, F_NAMEEQ,
    2226             :                     CStringGetDatum(dbname));
    2227          22 :         sysscan = systable_beginscan(pgdbrel, DatabaseNameIndexId, true,
    2228             :                                      NULL, 1, &scankey);
    2229          22 :         oldtuple = systable_getnext(sysscan);
    2230          22 :         if (!HeapTupleIsValid(oldtuple))    /* shouldn't happen... */
    2231           0 :             ereport(ERROR,
    2232             :                     (errcode(ERRCODE_UNDEFINED_DATABASE),
    2233             :                      errmsg("database \"%s\" does not exist", dbname)));
    2234          22 :         LockTuple(pgdbrel, &oldtuple->t_self, InplaceUpdateTupleLock);
    2235             : 
    2236          22 :         new_record[Anum_pg_database_dattablespace - 1] = ObjectIdGetDatum(dst_tblspcoid);
    2237          22 :         new_record_repl[Anum_pg_database_dattablespace - 1] = true;
    2238             : 
    2239          22 :         newtuple = heap_modify_tuple(oldtuple, RelationGetDescr(pgdbrel),
    2240             :                                      new_record,
    2241             :                                      new_record_nulls, new_record_repl);
    2242          22 :         CatalogTupleUpdate(pgdbrel, &oldtuple->t_self, newtuple);
    2243          22 :         UnlockTuple(pgdbrel, &oldtuple->t_self, InplaceUpdateTupleLock);
    2244             : 
    2245          22 :         InvokeObjectPostAlterHook(DatabaseRelationId, db_id, 0);
    2246             : 
    2247          22 :         systable_endscan(sysscan);
    2248             : 
    2249             :         /*
    2250             :          * Force another checkpoint here.  As in CREATE DATABASE, this is to
    2251             :          * ensure that we don't have to replay a committed
    2252             :          * XLOG_DBASE_CREATE_FILE_COPY operation, which would cause us to lose
    2253             :          * any unlogged operations done in the new DB tablespace before the
    2254             :          * next checkpoint.
    2255             :          */
    2256          22 :         RequestCheckpoint(CHECKPOINT_FAST | CHECKPOINT_FORCE | CHECKPOINT_WAIT);
    2257             : 
    2258             :         /*
    2259             :          * Force synchronous commit, thus minimizing the window between
    2260             :          * copying the database files and committal of the transaction. If we
    2261             :          * crash before committing, we'll leave an orphaned set of files on
    2262             :          * disk, which is not fatal but not good either.
    2263             :          */
    2264          22 :         ForceSyncCommit();
    2265             : 
    2266             :         /*
    2267             :          * Close pg_database, but keep lock till commit.
    2268             :          */
    2269          22 :         table_close(pgdbrel, NoLock);
    2270             :     }
    2271          22 :     PG_END_ENSURE_ERROR_CLEANUP(movedb_failure_callback,
    2272             :                                 PointerGetDatum(&fparms));
    2273             : 
    2274             :     /*
    2275             :      * Commit the transaction so that the pg_database update is committed. If
    2276             :      * we crash while removing files, the database won't be corrupt, we'll
    2277             :      * just leave some orphaned files in the old directory.
    2278             :      *
    2279             :      * (This is OK because we know we aren't inside a transaction block.)
    2280             :      *
    2281             :      * XXX would it be safe/better to do this inside the ensure block?  Not
    2282             :      * convinced it's a good idea; consider elog just after the transaction
    2283             :      * really commits.
    2284             :      */
    2285          22 :     PopActiveSnapshot();
    2286          22 :     CommitTransactionCommand();
    2287             : 
    2288             :     /* Start new transaction for the remaining work; don't need a snapshot */
    2289          22 :     StartTransactionCommand();
    2290             : 
    2291             :     /*
    2292             :      * Remove files from the old tablespace
    2293             :      */
    2294          22 :     if (!rmtree(src_dbpath, true))
    2295           0 :         ereport(WARNING,
    2296             :                 (errmsg("some useless files may be left behind in old database directory \"%s\"",
    2297             :                         src_dbpath)));
    2298             : 
    2299             :     /*
    2300             :      * Record the filesystem change in XLOG
    2301             :      */
    2302             :     {
    2303             :         xl_dbase_drop_rec xlrec;
    2304             : 
    2305          22 :         xlrec.db_id = db_id;
    2306          22 :         xlrec.ntablespaces = 1;
    2307             : 
    2308          22 :         XLogBeginInsert();
    2309          22 :         XLogRegisterData(&xlrec, sizeof(xl_dbase_drop_rec));
    2310          22 :         XLogRegisterData(&src_tblspcoid, sizeof(Oid));
    2311             : 
    2312          22 :         (void) XLogInsert(RM_DBASE_ID,
    2313             :                           XLOG_DBASE_DROP | XLR_SPECIAL_REL_UPDATE);
    2314             :     }
    2315             : 
    2316             :     /* Now it's safe to release the database lock */
    2317          22 :     UnlockSharedObjectForSession(DatabaseRelationId, db_id, 0,
    2318             :                                  AccessExclusiveLock);
    2319             : 
    2320          22 :     pfree(src_dbpath);
    2321          22 :     pfree(dst_dbpath);
    2322             : }
    2323             : 
    2324             : /* Error cleanup callback for movedb */
    2325             : static void
    2326           0 : movedb_failure_callback(int code, Datum arg)
    2327             : {
    2328           0 :     movedb_failure_params *fparms = (movedb_failure_params *) DatumGetPointer(arg);
    2329             :     char       *dstpath;
    2330             : 
    2331             :     /* Get rid of anything we managed to copy to the target directory */
    2332           0 :     dstpath = GetDatabasePath(fparms->dest_dboid, fparms->dest_tsoid);
    2333             : 
    2334           0 :     (void) rmtree(dstpath, true);
    2335             : 
    2336           0 :     pfree(dstpath);
    2337           0 : }
    2338             : 
    2339             : /*
    2340             :  * Process options and call dropdb function.
    2341             :  */
    2342             : void
    2343         124 : DropDatabase(ParseState *pstate, DropdbStmt *stmt)
    2344             : {
    2345         124 :     bool        force = false;
    2346             :     ListCell   *lc;
    2347             : 
    2348         150 :     foreach(lc, stmt->options)
    2349             :     {
    2350          26 :         DefElem    *opt = (DefElem *) lfirst(lc);
    2351             : 
    2352          26 :         if (strcmp(opt->defname, "force") == 0)
    2353          26 :             force = true;
    2354             :         else
    2355           0 :             ereport(ERROR,
    2356             :                     (errcode(ERRCODE_SYNTAX_ERROR),
    2357             :                      errmsg("unrecognized DROP DATABASE option \"%s\"", opt->defname),
    2358             :                      parser_errposition(pstate, opt->location)));
    2359             :     }
    2360             : 
    2361         124 :     dropdb(stmt->dbname, stmt->missing_ok, force);
    2362         106 : }
    2363             : 
    2364             : /*
    2365             :  * ALTER DATABASE name ...
    2366             :  */
    2367             : Oid
    2368          82 : AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
    2369             : {
    2370             :     Relation    rel;
    2371             :     Oid         dboid;
    2372             :     HeapTuple   tuple,
    2373             :                 newtuple;
    2374             :     Form_pg_database datform;
    2375             :     ScanKeyData scankey;
    2376             :     SysScanDesc scan;
    2377             :     ListCell   *option;
    2378          82 :     bool        dbistemplate = false;
    2379          82 :     bool        dballowconnections = true;
    2380          82 :     int         dbconnlimit = DATCONNLIMIT_UNLIMITED;
    2381          82 :     DefElem    *distemplate = NULL;
    2382          82 :     DefElem    *dallowconnections = NULL;
    2383          82 :     DefElem    *dconnlimit = NULL;
    2384          82 :     DefElem    *dtablespace = NULL;
    2385          82 :     Datum       new_record[Natts_pg_database] = {0};
    2386          82 :     bool        new_record_nulls[Natts_pg_database] = {0};
    2387          82 :     bool        new_record_repl[Natts_pg_database] = {0};
    2388             : 
    2389             :     /* Extract options from the statement node tree */
    2390         164 :     foreach(option, stmt->options)
    2391             :     {
    2392          82 :         DefElem    *defel = (DefElem *) lfirst(option);
    2393             : 
    2394          82 :         if (strcmp(defel->defname, "is_template") == 0)
    2395             :         {
    2396          20 :             if (distemplate)
    2397           0 :                 errorConflictingDefElem(defel, pstate);
    2398          20 :             distemplate = defel;
    2399             :         }
    2400          62 :         else if (strcmp(defel->defname, "allow_connections") == 0)
    2401             :         {
    2402          32 :             if (dallowconnections)
    2403           0 :                 errorConflictingDefElem(defel, pstate);
    2404          32 :             dallowconnections = defel;
    2405             :         }
    2406          30 :         else if (strcmp(defel->defname, "connection_limit") == 0)
    2407             :         {
    2408           8 :             if (dconnlimit)
    2409           0 :                 errorConflictingDefElem(defel, pstate);
    2410           8 :             dconnlimit = defel;
    2411             :         }
    2412          22 :         else if (strcmp(defel->defname, "tablespace") == 0)
    2413             :         {
    2414          22 :             if (dtablespace)
    2415           0 :                 errorConflictingDefElem(defel, pstate);
    2416          22 :             dtablespace = defel;
    2417             :         }
    2418             :         else
    2419           0 :             ereport(ERROR,
    2420             :                     (errcode(ERRCODE_SYNTAX_ERROR),
    2421             :                      errmsg("option \"%s\" not recognized", defel->defname),
    2422             :                      parser_errposition(pstate, defel->location)));
    2423             :     }
    2424             : 
    2425          82 :     if (dtablespace)
    2426             :     {
    2427             :         /*
    2428             :          * While the SET TABLESPACE syntax doesn't allow any other options,
    2429             :          * somebody could write "WITH TABLESPACE ...".  Forbid any other
    2430             :          * options from being specified in that case.
    2431             :          */
    2432          22 :         if (list_length(stmt->options) != 1)
    2433           0 :             ereport(ERROR,
    2434             :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    2435             :                      errmsg("option \"%s\" cannot be specified with other options",
    2436             :                             dtablespace->defname),
    2437             :                      parser_errposition(pstate, dtablespace->location)));
    2438             :         /* this case isn't allowed within a transaction block */
    2439          22 :         PreventInTransactionBlock(isTopLevel, "ALTER DATABASE SET TABLESPACE");
    2440          22 :         movedb(stmt->dbname, defGetString(dtablespace));
    2441          22 :         return InvalidOid;
    2442             :     }
    2443             : 
    2444          60 :     if (distemplate && distemplate->arg)
    2445          20 :         dbistemplate = defGetBoolean(distemplate);
    2446          60 :     if (dallowconnections && dallowconnections->arg)
    2447          32 :         dballowconnections = defGetBoolean(dallowconnections);
    2448          60 :     if (dconnlimit && dconnlimit->arg)
    2449             :     {
    2450           8 :         dbconnlimit = defGetInt32(dconnlimit);
    2451           8 :         if (dbconnlimit < DATCONNLIMIT_UNLIMITED)
    2452           0 :             ereport(ERROR,
    2453             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    2454             :                      errmsg("invalid connection limit: %d", dbconnlimit)));
    2455             :     }
    2456             : 
    2457             :     /*
    2458             :      * Get the old tuple.  We don't need a lock on the database per se,
    2459             :      * because we're not going to do anything that would mess up incoming
    2460             :      * connections.
    2461             :      */
    2462          60 :     rel = table_open(DatabaseRelationId, RowExclusiveLock);
    2463          60 :     ScanKeyInit(&scankey,
    2464             :                 Anum_pg_database_datname,
    2465             :                 BTEqualStrategyNumber, F_NAMEEQ,
    2466          60 :                 CStringGetDatum(stmt->dbname));
    2467          60 :     scan = systable_beginscan(rel, DatabaseNameIndexId, true,
    2468             :                               NULL, 1, &scankey);
    2469          60 :     tuple = systable_getnext(scan);
    2470          60 :     if (!HeapTupleIsValid(tuple))
    2471           0 :         ereport(ERROR,
    2472             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    2473             :                  errmsg("database \"%s\" does not exist", stmt->dbname)));
    2474          60 :     LockTuple(rel, &tuple->t_self, InplaceUpdateTupleLock);
    2475             : 
    2476          60 :     datform = (Form_pg_database) GETSTRUCT(tuple);
    2477          60 :     dboid = datform->oid;
    2478             : 
    2479          60 :     if (database_is_invalid_form(datform))
    2480             :     {
    2481           2 :         ereport(FATAL,
    2482             :                 errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
    2483             :                 errmsg("cannot alter invalid database \"%s\"", stmt->dbname),
    2484             :                 errhint("Use DROP DATABASE to drop invalid databases."));
    2485             :     }
    2486             : 
    2487          58 :     if (!object_ownercheck(DatabaseRelationId, dboid, GetUserId()))
    2488           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    2489           0 :                        stmt->dbname);
    2490             : 
    2491             :     /*
    2492             :      * In order to avoid getting locked out and having to go through
    2493             :      * standalone mode, we refuse to disallow connections to the database
    2494             :      * we're currently connected to.  Lockout can still happen with concurrent
    2495             :      * sessions but the likeliness of that is not high enough to worry about.
    2496             :      */
    2497          58 :     if (!dballowconnections && dboid == MyDatabaseId)
    2498           0 :         ereport(ERROR,
    2499             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    2500             :                  errmsg("cannot disallow connections for current database")));
    2501             : 
    2502             :     /*
    2503             :      * Build an updated tuple, perusing the information just obtained
    2504             :      */
    2505          58 :     if (distemplate)
    2506             :     {
    2507          20 :         new_record[Anum_pg_database_datistemplate - 1] = BoolGetDatum(dbistemplate);
    2508          20 :         new_record_repl[Anum_pg_database_datistemplate - 1] = true;
    2509             :     }
    2510          58 :     if (dallowconnections)
    2511             :     {
    2512          32 :         new_record[Anum_pg_database_datallowconn - 1] = BoolGetDatum(dballowconnections);
    2513          32 :         new_record_repl[Anum_pg_database_datallowconn - 1] = true;
    2514             :     }
    2515          58 :     if (dconnlimit)
    2516             :     {
    2517           6 :         new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(dbconnlimit);
    2518           6 :         new_record_repl[Anum_pg_database_datconnlimit - 1] = true;
    2519             :     }
    2520             : 
    2521          58 :     newtuple = heap_modify_tuple(tuple, RelationGetDescr(rel), new_record,
    2522             :                                  new_record_nulls, new_record_repl);
    2523          58 :     CatalogTupleUpdate(rel, &tuple->t_self, newtuple);
    2524          58 :     UnlockTuple(rel, &tuple->t_self, InplaceUpdateTupleLock);
    2525             : 
    2526          58 :     InvokeObjectPostAlterHook(DatabaseRelationId, dboid, 0);
    2527             : 
    2528          58 :     systable_endscan(scan);
    2529             : 
    2530             :     /* Close pg_database, but keep lock till commit */
    2531          58 :     table_close(rel, NoLock);
    2532             : 
    2533          58 :     return dboid;
    2534             : }
    2535             : 
    2536             : 
    2537             : /*
    2538             :  * ALTER DATABASE name REFRESH COLLATION VERSION
    2539             :  */
    2540             : ObjectAddress
    2541           6 : AlterDatabaseRefreshColl(AlterDatabaseRefreshCollStmt *stmt)
    2542             : {
    2543             :     Relation    rel;
    2544             :     ScanKeyData scankey;
    2545             :     SysScanDesc scan;
    2546             :     Oid         db_id;
    2547             :     HeapTuple   tuple;
    2548             :     Form_pg_database datForm;
    2549             :     ObjectAddress address;
    2550             :     Datum       datum;
    2551             :     bool        isnull;
    2552             :     char       *oldversion;
    2553             :     char       *newversion;
    2554             : 
    2555           6 :     rel = table_open(DatabaseRelationId, RowExclusiveLock);
    2556           6 :     ScanKeyInit(&scankey,
    2557             :                 Anum_pg_database_datname,
    2558             :                 BTEqualStrategyNumber, F_NAMEEQ,
    2559           6 :                 CStringGetDatum(stmt->dbname));
    2560           6 :     scan = systable_beginscan(rel, DatabaseNameIndexId, true,
    2561             :                               NULL, 1, &scankey);
    2562           6 :     tuple = systable_getnext(scan);
    2563           6 :     if (!HeapTupleIsValid(tuple))
    2564           0 :         ereport(ERROR,
    2565             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    2566             :                  errmsg("database \"%s\" does not exist", stmt->dbname)));
    2567             : 
    2568           6 :     datForm = (Form_pg_database) GETSTRUCT(tuple);
    2569           6 :     db_id = datForm->oid;
    2570             : 
    2571           6 :     if (!object_ownercheck(DatabaseRelationId, db_id, GetUserId()))
    2572           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    2573           0 :                        stmt->dbname);
    2574           6 :     LockTuple(rel, &tuple->t_self, InplaceUpdateTupleLock);
    2575             : 
    2576           6 :     datum = heap_getattr(tuple, Anum_pg_database_datcollversion, RelationGetDescr(rel), &isnull);
    2577           6 :     oldversion = isnull ? NULL : TextDatumGetCString(datum);
    2578             : 
    2579           6 :     if (datForm->datlocprovider == COLLPROVIDER_LIBC)
    2580             :     {
    2581           4 :         datum = heap_getattr(tuple, Anum_pg_database_datcollate, RelationGetDescr(rel), &isnull);
    2582           4 :         if (isnull)
    2583           0 :             elog(ERROR, "unexpected null in pg_database");
    2584             :     }
    2585             :     else
    2586             :     {
    2587           2 :         datum = heap_getattr(tuple, Anum_pg_database_datlocale, RelationGetDescr(rel), &isnull);
    2588           2 :         if (isnull)
    2589           0 :             elog(ERROR, "unexpected null in pg_database");
    2590             :     }
    2591             : 
    2592           6 :     newversion = get_collation_actual_version(datForm->datlocprovider,
    2593           6 :                                               TextDatumGetCString(datum));
    2594             : 
    2595             :     /* cannot change from NULL to non-NULL or vice versa */
    2596           6 :     if ((!oldversion && newversion) || (oldversion && !newversion))
    2597           0 :         elog(ERROR, "invalid collation version change");
    2598           6 :     else if (oldversion && newversion && strcmp(newversion, oldversion) != 0)
    2599           0 :     {
    2600           0 :         bool        nulls[Natts_pg_database] = {0};
    2601           0 :         bool        replaces[Natts_pg_database] = {0};
    2602           0 :         Datum       values[Natts_pg_database] = {0};
    2603             :         HeapTuple   newtuple;
    2604             : 
    2605           0 :         ereport(NOTICE,
    2606             :                 (errmsg("changing version from %s to %s",
    2607             :                         oldversion, newversion)));
    2608             : 
    2609           0 :         values[Anum_pg_database_datcollversion - 1] = CStringGetTextDatum(newversion);
    2610           0 :         replaces[Anum_pg_database_datcollversion - 1] = true;
    2611             : 
    2612           0 :         newtuple = heap_modify_tuple(tuple, RelationGetDescr(rel),
    2613             :                                      values, nulls, replaces);
    2614           0 :         CatalogTupleUpdate(rel, &tuple->t_self, newtuple);
    2615           0 :         heap_freetuple(newtuple);
    2616             :     }
    2617             :     else
    2618           6 :         ereport(NOTICE,
    2619             :                 (errmsg("version has not changed")));
    2620           6 :     UnlockTuple(rel, &tuple->t_self, InplaceUpdateTupleLock);
    2621             : 
    2622           6 :     InvokeObjectPostAlterHook(DatabaseRelationId, db_id, 0);
    2623             : 
    2624           6 :     ObjectAddressSet(address, DatabaseRelationId, db_id);
    2625             : 
    2626           6 :     systable_endscan(scan);
    2627             : 
    2628           6 :     table_close(rel, NoLock);
    2629             : 
    2630           6 :     return address;
    2631             : }
    2632             : 
    2633             : 
    2634             : /*
    2635             :  * ALTER DATABASE name SET ...
    2636             :  */
    2637             : Oid
    2638        1206 : AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
    2639             : {
    2640        1206 :     Oid         datid = get_database_oid(stmt->dbname, false);
    2641             : 
    2642             :     /*
    2643             :      * Obtain a lock on the database and make sure it didn't go away in the
    2644             :      * meantime.
    2645             :      */
    2646        1206 :     shdepLockAndCheckObject(DatabaseRelationId, datid);
    2647             : 
    2648        1206 :     if (!object_ownercheck(DatabaseRelationId, datid, GetUserId()))
    2649           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    2650           0 :                        stmt->dbname);
    2651             : 
    2652        1206 :     AlterSetting(datid, InvalidOid, stmt->setstmt);
    2653             : 
    2654        1202 :     UnlockSharedObject(DatabaseRelationId, datid, 0, AccessShareLock);
    2655             : 
    2656        1202 :     return datid;
    2657             : }
    2658             : 
    2659             : 
    2660             : /*
    2661             :  * ALTER DATABASE name OWNER TO newowner
    2662             :  */
    2663             : ObjectAddress
    2664          86 : AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
    2665             : {
    2666             :     Oid         db_id;
    2667             :     HeapTuple   tuple;
    2668             :     Relation    rel;
    2669             :     ScanKeyData scankey;
    2670             :     SysScanDesc scan;
    2671             :     Form_pg_database datForm;
    2672             :     ObjectAddress address;
    2673             : 
    2674             :     /*
    2675             :      * Get the old tuple.  We don't need a lock on the database per se,
    2676             :      * because we're not going to do anything that would mess up incoming
    2677             :      * connections.
    2678             :      */
    2679          86 :     rel = table_open(DatabaseRelationId, RowExclusiveLock);
    2680          86 :     ScanKeyInit(&scankey,
    2681             :                 Anum_pg_database_datname,
    2682             :                 BTEqualStrategyNumber, F_NAMEEQ,
    2683             :                 CStringGetDatum(dbname));
    2684          86 :     scan = systable_beginscan(rel, DatabaseNameIndexId, true,
    2685             :                               NULL, 1, &scankey);
    2686          86 :     tuple = systable_getnext(scan);
    2687          86 :     if (!HeapTupleIsValid(tuple))
    2688           0 :         ereport(ERROR,
    2689             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    2690             :                  errmsg("database \"%s\" does not exist", dbname)));
    2691             : 
    2692          86 :     datForm = (Form_pg_database) GETSTRUCT(tuple);
    2693          86 :     db_id = datForm->oid;
    2694             : 
    2695             :     /*
    2696             :      * If the new owner is the same as the existing owner, consider the
    2697             :      * command to have succeeded.  This is to be consistent with other
    2698             :      * objects.
    2699             :      */
    2700          86 :     if (datForm->datdba != newOwnerId)
    2701             :     {
    2702             :         Datum       repl_val[Natts_pg_database];
    2703          30 :         bool        repl_null[Natts_pg_database] = {0};
    2704          30 :         bool        repl_repl[Natts_pg_database] = {0};
    2705             :         Acl        *newAcl;
    2706             :         Datum       aclDatum;
    2707             :         bool        isNull;
    2708             :         HeapTuple   newtuple;
    2709             : 
    2710             :         /* Otherwise, must be owner of the existing object */
    2711          30 :         if (!object_ownercheck(DatabaseRelationId, db_id, GetUserId()))
    2712           0 :             aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    2713             :                            dbname);
    2714             : 
    2715             :         /* Must be able to become new owner */
    2716          30 :         check_can_set_role(GetUserId(), newOwnerId);
    2717             : 
    2718             :         /*
    2719             :          * must have createdb rights
    2720             :          *
    2721             :          * NOTE: This is different from other alter-owner checks in that the
    2722             :          * current user is checked for createdb privileges instead of the
    2723             :          * destination owner.  This is consistent with the CREATE case for
    2724             :          * databases.  Because superusers will always have this right, we need
    2725             :          * no special case for them.
    2726             :          */
    2727          30 :         if (!have_createdb_privilege())
    2728           0 :             ereport(ERROR,
    2729             :                     (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    2730             :                      errmsg("permission denied to change owner of database")));
    2731             : 
    2732          30 :         LockTuple(rel, &tuple->t_self, InplaceUpdateTupleLock);
    2733             : 
    2734          30 :         repl_repl[Anum_pg_database_datdba - 1] = true;
    2735          30 :         repl_val[Anum_pg_database_datdba - 1] = ObjectIdGetDatum(newOwnerId);
    2736             : 
    2737             :         /*
    2738             :          * Determine the modified ACL for the new owner.  This is only
    2739             :          * necessary when the ACL is non-null.
    2740             :          */
    2741          30 :         aclDatum = heap_getattr(tuple,
    2742             :                                 Anum_pg_database_datacl,
    2743             :                                 RelationGetDescr(rel),
    2744             :                                 &isNull);
    2745          30 :         if (!isNull)
    2746             :         {
    2747           0 :             newAcl = aclnewowner(DatumGetAclP(aclDatum),
    2748             :                                  datForm->datdba, newOwnerId);
    2749           0 :             repl_repl[Anum_pg_database_datacl - 1] = true;
    2750           0 :             repl_val[Anum_pg_database_datacl - 1] = PointerGetDatum(newAcl);
    2751             :         }
    2752             : 
    2753          30 :         newtuple = heap_modify_tuple(tuple, RelationGetDescr(rel), repl_val, repl_null, repl_repl);
    2754          30 :         CatalogTupleUpdate(rel, &newtuple->t_self, newtuple);
    2755          30 :         UnlockTuple(rel, &tuple->t_self, InplaceUpdateTupleLock);
    2756             : 
    2757          30 :         heap_freetuple(newtuple);
    2758             : 
    2759             :         /* Update owner dependency reference */
    2760          30 :         changeDependencyOnOwner(DatabaseRelationId, db_id, newOwnerId);
    2761             :     }
    2762             : 
    2763          86 :     InvokeObjectPostAlterHook(DatabaseRelationId, db_id, 0);
    2764             : 
    2765          86 :     ObjectAddressSet(address, DatabaseRelationId, db_id);
    2766             : 
    2767          86 :     systable_endscan(scan);
    2768             : 
    2769             :     /* Close pg_database, but keep lock till commit */
    2770          86 :     table_close(rel, NoLock);
    2771             : 
    2772          86 :     return address;
    2773             : }
    2774             : 
    2775             : 
    2776             : Datum
    2777          96 : pg_database_collation_actual_version(PG_FUNCTION_ARGS)
    2778             : {
    2779          96 :     Oid         dbid = PG_GETARG_OID(0);
    2780             :     HeapTuple   tp;
    2781             :     char        datlocprovider;
    2782             :     Datum       datum;
    2783             :     char       *version;
    2784             : 
    2785          96 :     tp = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(dbid));
    2786          96 :     if (!HeapTupleIsValid(tp))
    2787           0 :         ereport(ERROR,
    2788             :                 (errcode(ERRCODE_UNDEFINED_OBJECT),
    2789             :                  errmsg("database with OID %u does not exist", dbid)));
    2790             : 
    2791          96 :     datlocprovider = ((Form_pg_database) GETSTRUCT(tp))->datlocprovider;
    2792             : 
    2793          96 :     if (datlocprovider == COLLPROVIDER_LIBC)
    2794          82 :         datum = SysCacheGetAttrNotNull(DATABASEOID, tp, Anum_pg_database_datcollate);
    2795             :     else
    2796          14 :         datum = SysCacheGetAttrNotNull(DATABASEOID, tp, Anum_pg_database_datlocale);
    2797             : 
    2798          96 :     version = get_collation_actual_version(datlocprovider,
    2799          96 :                                            TextDatumGetCString(datum));
    2800             : 
    2801          96 :     ReleaseSysCache(tp);
    2802             : 
    2803          96 :     if (version)
    2804          68 :         PG_RETURN_TEXT_P(cstring_to_text(version));
    2805             :     else
    2806          28 :         PG_RETURN_NULL();
    2807             : }
    2808             : 
    2809             : 
    2810             : /*
    2811             :  * Helper functions
    2812             :  */
    2813             : 
    2814             : /*
    2815             :  * Look up info about the database named "name".  If the database exists,
    2816             :  * obtain the specified lock type on it, fill in any of the remaining
    2817             :  * parameters that aren't NULL, and return true.  If no such database,
    2818             :  * return false.
    2819             :  */
    2820             : static bool
    2821         948 : get_db_info(const char *name, LOCKMODE lockmode,
    2822             :             Oid *dbIdP, Oid *ownerIdP,
    2823             :             int *encodingP, bool *dbIsTemplateP, bool *dbAllowConnP, bool *dbHasLoginEvtP,
    2824             :             TransactionId *dbFrozenXidP, MultiXactId *dbMinMultiP,
    2825             :             Oid *dbTablespace, char **dbCollate, char **dbCtype, char **dbLocale,
    2826             :             char **dbIcurules,
    2827             :             char *dbLocProvider,
    2828             :             char **dbCollversion)
    2829             : {
    2830         948 :     bool        result = false;
    2831             :     Relation    relation;
    2832             : 
    2833             :     Assert(name);
    2834             : 
    2835             :     /* Caller may wish to grab a better lock on pg_database beforehand... */
    2836         948 :     relation = table_open(DatabaseRelationId, AccessShareLock);
    2837             : 
    2838             :     /*
    2839             :      * Loop covers the rare case where the database is renamed before we can
    2840             :      * lock it.  We try again just in case we can find a new one of the same
    2841             :      * name.
    2842             :      */
    2843             :     for (;;)
    2844           0 :     {
    2845             :         ScanKeyData scanKey;
    2846             :         SysScanDesc scan;
    2847             :         HeapTuple   tuple;
    2848             :         Oid         dbOid;
    2849             : 
    2850             :         /*
    2851             :          * there's no syscache for database-indexed-by-name, so must do it the
    2852             :          * hard way
    2853             :          */
    2854         948 :         ScanKeyInit(&scanKey,
    2855             :                     Anum_pg_database_datname,
    2856             :                     BTEqualStrategyNumber, F_NAMEEQ,
    2857             :                     CStringGetDatum(name));
    2858             : 
    2859         948 :         scan = systable_beginscan(relation, DatabaseNameIndexId, true,
    2860             :                                   NULL, 1, &scanKey);
    2861             : 
    2862         948 :         tuple = systable_getnext(scan);
    2863             : 
    2864         948 :         if (!HeapTupleIsValid(tuple))
    2865             :         {
    2866             :             /* definitely no database of that name */
    2867          32 :             systable_endscan(scan);
    2868          32 :             break;
    2869             :         }
    2870             : 
    2871         916 :         dbOid = ((Form_pg_database) GETSTRUCT(tuple))->oid;
    2872             : 
    2873         916 :         systable_endscan(scan);
    2874             : 
    2875             :         /*
    2876             :          * Now that we have a database OID, we can try to lock the DB.
    2877             :          */
    2878         916 :         if (lockmode != NoLock)
    2879         916 :             LockSharedObject(DatabaseRelationId, dbOid, 0, lockmode);
    2880             : 
    2881             :         /*
    2882             :          * And now, re-fetch the tuple by OID.  If it's still there and still
    2883             :          * the same name, we win; else, drop the lock and loop back to try
    2884             :          * again.
    2885             :          */
    2886         916 :         tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(dbOid));
    2887         916 :         if (HeapTupleIsValid(tuple))
    2888             :         {
    2889         916 :             Form_pg_database dbform = (Form_pg_database) GETSTRUCT(tuple);
    2890             : 
    2891         916 :             if (strcmp(name, NameStr(dbform->datname)) == 0)
    2892             :             {
    2893             :                 Datum       datum;
    2894             :                 bool        isnull;
    2895             : 
    2896             :                 /* oid of the database */
    2897         916 :                 if (dbIdP)
    2898         916 :                     *dbIdP = dbOid;
    2899             :                 /* oid of the owner */
    2900         916 :                 if (ownerIdP)
    2901         790 :                     *ownerIdP = dbform->datdba;
    2902             :                 /* character encoding */
    2903         916 :                 if (encodingP)
    2904         790 :                     *encodingP = dbform->encoding;
    2905             :                 /* allowed as template? */
    2906         916 :                 if (dbIsTemplateP)
    2907         882 :                     *dbIsTemplateP = dbform->datistemplate;
    2908             :                 /* Has on login event trigger? */
    2909         916 :                 if (dbHasLoginEvtP)
    2910         790 :                     *dbHasLoginEvtP = dbform->dathasloginevt;
    2911             :                 /* allowing connections? */
    2912         916 :                 if (dbAllowConnP)
    2913         790 :                     *dbAllowConnP = dbform->datallowconn;
    2914             :                 /* limit of frozen XIDs */
    2915         916 :                 if (dbFrozenXidP)
    2916         790 :                     *dbFrozenXidP = dbform->datfrozenxid;
    2917             :                 /* minimum MultiXactId */
    2918         916 :                 if (dbMinMultiP)
    2919         790 :                     *dbMinMultiP = dbform->datminmxid;
    2920             :                 /* default tablespace for this database */
    2921         916 :                 if (dbTablespace)
    2922         812 :                     *dbTablespace = dbform->dattablespace;
    2923             :                 /* default locale settings for this database */
    2924         916 :                 if (dbLocProvider)
    2925         790 :                     *dbLocProvider = dbform->datlocprovider;
    2926         916 :                 if (dbCollate)
    2927             :                 {
    2928         790 :                     datum = SysCacheGetAttrNotNull(DATABASEOID, tuple, Anum_pg_database_datcollate);
    2929         790 :                     *dbCollate = TextDatumGetCString(datum);
    2930             :                 }
    2931         916 :                 if (dbCtype)
    2932             :                 {
    2933         790 :                     datum = SysCacheGetAttrNotNull(DATABASEOID, tuple, Anum_pg_database_datctype);
    2934         790 :                     *dbCtype = TextDatumGetCString(datum);
    2935             :                 }
    2936         916 :                 if (dbLocale)
    2937             :                 {
    2938         790 :                     datum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_datlocale, &isnull);
    2939         790 :                     if (isnull)
    2940         732 :                         *dbLocale = NULL;
    2941             :                     else
    2942          58 :                         *dbLocale = TextDatumGetCString(datum);
    2943             :                 }
    2944         916 :                 if (dbIcurules)
    2945             :                 {
    2946         790 :                     datum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_daticurules, &isnull);
    2947         790 :                     if (isnull)
    2948         790 :                         *dbIcurules = NULL;
    2949             :                     else
    2950           0 :                         *dbIcurules = TextDatumGetCString(datum);
    2951             :                 }
    2952         916 :                 if (dbCollversion)
    2953             :                 {
    2954         790 :                     datum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_datcollversion, &isnull);
    2955         790 :                     if (isnull)
    2956         476 :                         *dbCollversion = NULL;
    2957             :                     else
    2958         314 :                         *dbCollversion = TextDatumGetCString(datum);
    2959             :                 }
    2960         916 :                 ReleaseSysCache(tuple);
    2961         916 :                 result = true;
    2962         916 :                 break;
    2963             :             }
    2964             :             /* can only get here if it was just renamed */
    2965           0 :             ReleaseSysCache(tuple);
    2966             :         }
    2967             : 
    2968           0 :         if (lockmode != NoLock)
    2969           0 :             UnlockSharedObject(DatabaseRelationId, dbOid, 0, lockmode);
    2970             :     }
    2971             : 
    2972         948 :     table_close(relation, AccessShareLock);
    2973             : 
    2974         948 :     return result;
    2975             : }
    2976             : 
    2977             : /* Check if current user has createdb privileges */
    2978             : bool
    2979         868 : have_createdb_privilege(void)
    2980             : {
    2981         868 :     bool        result = false;
    2982             :     HeapTuple   utup;
    2983             : 
    2984             :     /* Superusers can always do everything */
    2985         868 :     if (superuser())
    2986         832 :         return true;
    2987             : 
    2988          36 :     utup = SearchSysCache1(AUTHOID, ObjectIdGetDatum(GetUserId()));
    2989          36 :     if (HeapTupleIsValid(utup))
    2990             :     {
    2991          36 :         result = ((Form_pg_authid) GETSTRUCT(utup))->rolcreatedb;
    2992          36 :         ReleaseSysCache(utup);
    2993             :     }
    2994          36 :     return result;
    2995             : }
    2996             : 
    2997             : /*
    2998             :  * Remove tablespace directories
    2999             :  *
    3000             :  * We don't know what tablespaces db_id is using, so iterate through all
    3001             :  * tablespaces removing <tablespace>/db_id
    3002             :  */
    3003             : static void
    3004          94 : remove_dbtablespaces(Oid db_id)
    3005             : {
    3006             :     Relation    rel;
    3007             :     TableScanDesc scan;
    3008             :     HeapTuple   tuple;
    3009          94 :     List       *ltblspc = NIL;
    3010             :     ListCell   *cell;
    3011             :     int         ntblspc;
    3012             :     int         i;
    3013             :     Oid        *tablespace_ids;
    3014             : 
    3015          94 :     rel = table_open(TableSpaceRelationId, AccessShareLock);
    3016          94 :     scan = table_beginscan_catalog(rel, 0, NULL);
    3017         348 :     while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
    3018             :     {
    3019         254 :         Form_pg_tablespace spcform = (Form_pg_tablespace) GETSTRUCT(tuple);
    3020         254 :         Oid         dsttablespace = spcform->oid;
    3021             :         char       *dstpath;
    3022             :         struct stat st;
    3023             : 
    3024             :         /* Don't mess with the global tablespace */
    3025         254 :         if (dsttablespace == GLOBALTABLESPACE_OID)
    3026         160 :             continue;
    3027             : 
    3028         160 :         dstpath = GetDatabasePath(db_id, dsttablespace);
    3029             : 
    3030         160 :         if (lstat(dstpath, &st) < 0 || !S_ISDIR(st.st_mode))
    3031             :         {
    3032             :             /* Assume we can ignore it */
    3033          66 :             pfree(dstpath);
    3034          66 :             continue;
    3035             :         }
    3036             : 
    3037          94 :         if (!rmtree(dstpath, true))
    3038           0 :             ereport(WARNING,
    3039             :                     (errmsg("some useless files may be left behind in old database directory \"%s\"",
    3040             :                             dstpath)));
    3041             : 
    3042          94 :         ltblspc = lappend_oid(ltblspc, dsttablespace);
    3043          94 :         pfree(dstpath);
    3044             :     }
    3045             : 
    3046          94 :     ntblspc = list_length(ltblspc);
    3047          94 :     if (ntblspc == 0)
    3048             :     {
    3049           0 :         table_endscan(scan);
    3050           0 :         table_close(rel, AccessShareLock);
    3051           0 :         return;
    3052             :     }
    3053             : 
    3054          94 :     tablespace_ids = (Oid *) palloc(ntblspc * sizeof(Oid));
    3055          94 :     i = 0;
    3056         188 :     foreach(cell, ltblspc)
    3057          94 :         tablespace_ids[i++] = lfirst_oid(cell);
    3058             : 
    3059             :     /* Record the filesystem change in XLOG */
    3060             :     {
    3061             :         xl_dbase_drop_rec xlrec;
    3062             : 
    3063          94 :         xlrec.db_id = db_id;
    3064          94 :         xlrec.ntablespaces = ntblspc;
    3065             : 
    3066          94 :         XLogBeginInsert();
    3067          94 :         XLogRegisterData(&xlrec, MinSizeOfDbaseDropRec);
    3068          94 :         XLogRegisterData(tablespace_ids, ntblspc * sizeof(Oid));
    3069             : 
    3070          94 :         (void) XLogInsert(RM_DBASE_ID,
    3071             :                           XLOG_DBASE_DROP | XLR_SPECIAL_REL_UPDATE);
    3072             :     }
    3073             : 
    3074          94 :     list_free(ltblspc);
    3075          94 :     pfree(tablespace_ids);
    3076             : 
    3077          94 :     table_endscan(scan);
    3078          94 :     table_close(rel, AccessShareLock);
    3079             : }
    3080             : 
    3081             : /*
    3082             :  * Check for existing files that conflict with a proposed new DB OID;
    3083             :  * return true if there are any
    3084             :  *
    3085             :  * If there were a subdirectory in any tablespace matching the proposed new
    3086             :  * OID, we'd get a create failure due to the duplicate name ... and then we'd
    3087             :  * try to remove that already-existing subdirectory during the cleanup in
    3088             :  * remove_dbtablespaces.  Nuking existing files seems like a bad idea, so
    3089             :  * instead we make this extra check before settling on the OID of the new
    3090             :  * database.  This exactly parallels what GetNewRelFileNumber() does for table
    3091             :  * relfilenumber values.
    3092             :  */
    3093             : static bool
    3094         764 : check_db_file_conflict(Oid db_id)
    3095             : {
    3096         764 :     bool        result = false;
    3097             :     Relation    rel;
    3098             :     TableScanDesc scan;
    3099             :     HeapTuple   tuple;
    3100             : 
    3101         764 :     rel = table_open(TableSpaceRelationId, AccessShareLock);
    3102         764 :     scan = table_beginscan_catalog(rel, 0, NULL);
    3103        2432 :     while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
    3104             :     {
    3105        1668 :         Form_pg_tablespace spcform = (Form_pg_tablespace) GETSTRUCT(tuple);
    3106        1668 :         Oid         dsttablespace = spcform->oid;
    3107             :         char       *dstpath;
    3108             :         struct stat st;
    3109             : 
    3110             :         /* Don't mess with the global tablespace */
    3111        1668 :         if (dsttablespace == GLOBALTABLESPACE_OID)
    3112         764 :             continue;
    3113             : 
    3114         904 :         dstpath = GetDatabasePath(db_id, dsttablespace);
    3115             : 
    3116         904 :         if (lstat(dstpath, &st) == 0)
    3117             :         {
    3118             :             /* Found a conflicting file (or directory, whatever) */
    3119           0 :             pfree(dstpath);
    3120           0 :             result = true;
    3121           0 :             break;
    3122             :         }
    3123             : 
    3124         904 :         pfree(dstpath);
    3125             :     }
    3126             : 
    3127         764 :     table_endscan(scan);
    3128         764 :     table_close(rel, AccessShareLock);
    3129             : 
    3130         764 :     return result;
    3131             : }
    3132             : 
    3133             : /*
    3134             :  * Issue a suitable errdetail message for a busy database
    3135             :  */
    3136             : static int
    3137           0 : errdetail_busy_db(int notherbackends, int npreparedxacts)
    3138             : {
    3139           0 :     if (notherbackends > 0 && npreparedxacts > 0)
    3140             : 
    3141             :         /*
    3142             :          * We don't deal with singular versus plural here, since gettext
    3143             :          * doesn't support multiple plurals in one string.
    3144             :          */
    3145           0 :         errdetail("There are %d other session(s) and %d prepared transaction(s) using the database.",
    3146             :                   notherbackends, npreparedxacts);
    3147           0 :     else if (notherbackends > 0)
    3148           0 :         errdetail_plural("There is %d other session using the database.",
    3149             :                          "There are %d other sessions using the database.",
    3150             :                          notherbackends,
    3151             :                          notherbackends);
    3152             :     else
    3153           0 :         errdetail_plural("There is %d prepared transaction using the database.",
    3154             :                          "There are %d prepared transactions using the database.",
    3155             :                          npreparedxacts,
    3156             :                          npreparedxacts);
    3157           0 :     return 0;                   /* just to keep ereport macro happy */
    3158             : }
    3159             : 
    3160             : /*
    3161             :  * get_database_oid - given a database name, look up the OID
    3162             :  *
    3163             :  * If missing_ok is false, throw an error if database name not found.  If
    3164             :  * true, just return InvalidOid.
    3165             :  */
    3166             : Oid
    3167        2966 : get_database_oid(const char *dbname, bool missing_ok)
    3168             : {
    3169             :     Relation    pg_database;
    3170             :     ScanKeyData entry[1];
    3171             :     SysScanDesc scan;
    3172             :     HeapTuple   dbtuple;
    3173             :     Oid         oid;
    3174             : 
    3175             :     /*
    3176             :      * There's no syscache for pg_database indexed by name, so we must look
    3177             :      * the hard way.
    3178             :      */
    3179        2966 :     pg_database = table_open(DatabaseRelationId, AccessShareLock);
    3180        2966 :     ScanKeyInit(&entry[0],
    3181             :                 Anum_pg_database_datname,
    3182             :                 BTEqualStrategyNumber, F_NAMEEQ,
    3183             :                 CStringGetDatum(dbname));
    3184        2966 :     scan = systable_beginscan(pg_database, DatabaseNameIndexId, true,
    3185             :                               NULL, 1, entry);
    3186             : 
    3187        2966 :     dbtuple = systable_getnext(scan);
    3188             : 
    3189             :     /* We assume that there can be at most one matching tuple */
    3190        2966 :     if (HeapTupleIsValid(dbtuple))
    3191        2154 :         oid = ((Form_pg_database) GETSTRUCT(dbtuple))->oid;
    3192             :     else
    3193         812 :         oid = InvalidOid;
    3194             : 
    3195        2966 :     systable_endscan(scan);
    3196        2966 :     table_close(pg_database, AccessShareLock);
    3197             : 
    3198        2966 :     if (!OidIsValid(oid) && !missing_ok)
    3199           6 :         ereport(ERROR,
    3200             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    3201             :                  errmsg("database \"%s\" does not exist",
    3202             :                         dbname)));
    3203             : 
    3204        2960 :     return oid;
    3205             : }
    3206             : 
    3207             : 
    3208             : /*
    3209             :  * While dropping a database the pg_database row is marked invalid, but the
    3210             :  * catalog contents still exist. Connections to such a database are not
    3211             :  * allowed.
    3212             :  */
    3213             : bool
    3214       55274 : database_is_invalid_form(Form_pg_database datform)
    3215             : {
    3216       55274 :     return datform->datconnlimit == DATCONNLIMIT_INVALID_DB;
    3217             : }
    3218             : 
    3219             : 
    3220             : /*
    3221             :  * Convenience wrapper around database_is_invalid_form()
    3222             :  */
    3223             : bool
    3224         790 : database_is_invalid_oid(Oid dboid)
    3225             : {
    3226             :     HeapTuple   dbtup;
    3227             :     Form_pg_database dbform;
    3228             :     bool        invalid;
    3229             : 
    3230         790 :     dbtup = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(dboid));
    3231         790 :     if (!HeapTupleIsValid(dbtup))
    3232           0 :         elog(ERROR, "cache lookup failed for database %u", dboid);
    3233         790 :     dbform = (Form_pg_database) GETSTRUCT(dbtup);
    3234             : 
    3235         790 :     invalid = database_is_invalid_form(dbform);
    3236             : 
    3237         790 :     ReleaseSysCache(dbtup);
    3238             : 
    3239         790 :     return invalid;
    3240             : }
    3241             : 
    3242             : 
    3243             : /*
    3244             :  * recovery_create_dbdir()
    3245             :  *
    3246             :  * During recovery, there's a case where we validly need to recover a missing
    3247             :  * tablespace directory so that recovery can continue.  This happens when
    3248             :  * recovery wants to create a database but the holding tablespace has been
    3249             :  * removed before the server stopped.  Since we expect that the directory will
    3250             :  * be gone before reaching recovery consistency, and we have no knowledge about
    3251             :  * the tablespace other than its OID here, we create a real directory under
    3252             :  * pg_tblspc here instead of restoring the symlink.
    3253             :  *
    3254             :  * If only_tblspc is true, then the requested directory must be in pg_tblspc/
    3255             :  */
    3256             : static void
    3257          46 : recovery_create_dbdir(char *path, bool only_tblspc)
    3258             : {
    3259             :     struct stat st;
    3260             : 
    3261             :     Assert(RecoveryInProgress());
    3262             : 
    3263          46 :     if (stat(path, &st) == 0)
    3264          46 :         return;
    3265             : 
    3266           0 :     if (only_tblspc && strstr(path, PG_TBLSPC_DIR_SLASH) == NULL)
    3267           0 :         elog(PANIC, "requested to created invalid directory: %s", path);
    3268             : 
    3269           0 :     if (reachedConsistency && !allow_in_place_tablespaces)
    3270           0 :         ereport(PANIC,
    3271             :                 errmsg("missing directory \"%s\"", path));
    3272             : 
    3273           0 :     elog(reachedConsistency ? WARNING : DEBUG1,
    3274             :          "creating missing directory: %s", path);
    3275             : 
    3276           0 :     if (pg_mkdir_p(path, pg_dir_create_mode) != 0)
    3277           0 :         ereport(PANIC,
    3278             :                 errmsg("could not create missing directory \"%s\": %m", path));
    3279             : }
    3280             : 
    3281             : 
    3282             : /*
    3283             :  * DATABASE resource manager's routines
    3284             :  */
    3285             : void
    3286          84 : dbase_redo(XLogReaderState *record)
    3287             : {
    3288          84 :     uint8       info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
    3289             : 
    3290             :     /* Backup blocks are not used in dbase records */
    3291             :     Assert(!XLogRecHasAnyBlockRefs(record));
    3292             : 
    3293          84 :     if (info == XLOG_DBASE_CREATE_FILE_COPY)
    3294             :     {
    3295          10 :         xl_dbase_create_file_copy_rec *xlrec =
    3296          10 :             (xl_dbase_create_file_copy_rec *) XLogRecGetData(record);
    3297             :         char       *src_path;
    3298             :         char       *dst_path;
    3299             :         char       *parent_path;
    3300             :         struct stat st;
    3301             : 
    3302          10 :         src_path = GetDatabasePath(xlrec->src_db_id, xlrec->src_tablespace_id);
    3303          10 :         dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
    3304             : 
    3305             :         /*
    3306             :          * Our theory for replaying a CREATE is to forcibly drop the target
    3307             :          * subdirectory if present, then re-copy the source data. This may be
    3308             :          * more work than needed, but it is simple to implement.
    3309             :          */
    3310          10 :         if (stat(dst_path, &st) == 0 && S_ISDIR(st.st_mode))
    3311             :         {
    3312           0 :             if (!rmtree(dst_path, true))
    3313             :                 /* If this failed, copydir() below is going to error. */
    3314           0 :                 ereport(WARNING,
    3315             :                         (errmsg("some useless files may be left behind in old database directory \"%s\"",
    3316             :                                 dst_path)));
    3317             :         }
    3318             : 
    3319             :         /*
    3320             :          * If the parent of the target path doesn't exist, create it now. This
    3321             :          * enables us to create the target underneath later.
    3322             :          */
    3323          10 :         parent_path = pstrdup(dst_path);
    3324          10 :         get_parent_directory(parent_path);
    3325          10 :         if (stat(parent_path, &st) < 0)
    3326             :         {
    3327           0 :             if (errno != ENOENT)
    3328           0 :                 ereport(FATAL,
    3329             :                         errmsg("could not stat directory \"%s\": %m",
    3330             :                                dst_path));
    3331             : 
    3332             :             /* create the parent directory if needed and valid */
    3333           0 :             recovery_create_dbdir(parent_path, true);
    3334             :         }
    3335          10 :         pfree(parent_path);
    3336             : 
    3337             :         /*
    3338             :          * There's a case where the copy source directory is missing for the
    3339             :          * same reason above.  Create the empty source directory so that
    3340             :          * copydir below doesn't fail.  The directory will be dropped soon by
    3341             :          * recovery.
    3342             :          */
    3343          10 :         if (stat(src_path, &st) < 0 && errno == ENOENT)
    3344           0 :             recovery_create_dbdir(src_path, false);
    3345             : 
    3346             :         /*
    3347             :          * Force dirty buffers out to disk, to ensure source database is
    3348             :          * up-to-date for the copy.
    3349             :          */
    3350          10 :         FlushDatabaseBuffers(xlrec->src_db_id);
    3351             : 
    3352             :         /* Close all smgr fds in all backends. */
    3353          10 :         WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_SMGRRELEASE));
    3354             : 
    3355             :         /*
    3356             :          * Copy this subdirectory to the new location
    3357             :          *
    3358             :          * We don't need to copy subdirectories
    3359             :          */
    3360          10 :         copydir(src_path, dst_path, false);
    3361             : 
    3362          10 :         pfree(src_path);
    3363          10 :         pfree(dst_path);
    3364             :     }
    3365          74 :     else if (info == XLOG_DBASE_CREATE_WAL_LOG)
    3366             :     {
    3367          46 :         xl_dbase_create_wal_log_rec *xlrec =
    3368          46 :             (xl_dbase_create_wal_log_rec *) XLogRecGetData(record);
    3369             :         char       *dbpath;
    3370             :         char       *parent_path;
    3371             : 
    3372          46 :         dbpath = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
    3373             : 
    3374             :         /* create the parent directory if needed and valid */
    3375          46 :         parent_path = pstrdup(dbpath);
    3376          46 :         get_parent_directory(parent_path);
    3377          46 :         recovery_create_dbdir(parent_path, true);
    3378             : 
    3379             :         /* Create the database directory with the version file. */
    3380          46 :         CreateDirAndVersionFile(dbpath, xlrec->db_id, xlrec->tablespace_id,
    3381             :                                 true);
    3382          46 :         pfree(dbpath);
    3383             :     }
    3384          28 :     else if (info == XLOG_DBASE_DROP)
    3385             :     {
    3386          28 :         xl_dbase_drop_rec *xlrec = (xl_dbase_drop_rec *) XLogRecGetData(record);
    3387             :         char       *dst_path;
    3388             :         int         i;
    3389             : 
    3390          28 :         if (InHotStandby)
    3391             :         {
    3392             :             /*
    3393             :              * Lock database while we resolve conflicts to ensure that
    3394             :              * InitPostgres() cannot fully re-execute concurrently. This
    3395             :              * avoids backends re-connecting automatically to same database,
    3396             :              * which can happen in some cases.
    3397             :              *
    3398             :              * This will lock out walsenders trying to connect to db-specific
    3399             :              * slots for logical decoding too, so it's safe for us to drop
    3400             :              * slots.
    3401             :              */
    3402          28 :             LockSharedObjectForSession(DatabaseRelationId, xlrec->db_id, 0, AccessExclusiveLock);
    3403          28 :             ResolveRecoveryConflictWithDatabase(xlrec->db_id);
    3404             :         }
    3405             : 
    3406             :         /* Drop any database-specific replication slots */
    3407          28 :         ReplicationSlotsDropDBSlots(xlrec->db_id);
    3408             : 
    3409             :         /* Drop pages for this database that are in the shared buffer cache */
    3410          28 :         DropDatabaseBuffers(xlrec->db_id);
    3411             : 
    3412             :         /* Also, clean out any fsync requests that might be pending in md.c */
    3413          28 :         ForgetDatabaseSyncRequests(xlrec->db_id);
    3414             : 
    3415             :         /* Clean out the xlog relcache too */
    3416          28 :         XLogDropDatabase(xlrec->db_id);
    3417             : 
    3418             :         /* Close all smgr fds in all backends. */
    3419          28 :         WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_SMGRRELEASE));
    3420             : 
    3421          56 :         for (i = 0; i < xlrec->ntablespaces; i++)
    3422             :         {
    3423          28 :             dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_ids[i]);
    3424             : 
    3425             :             /* And remove the physical files */
    3426          28 :             if (!rmtree(dst_path, true))
    3427           0 :                 ereport(WARNING,
    3428             :                         (errmsg("some useless files may be left behind in old database directory \"%s\"",
    3429             :                                 dst_path)));
    3430          28 :             pfree(dst_path);
    3431             :         }
    3432             : 
    3433          28 :         if (InHotStandby)
    3434             :         {
    3435             :             /*
    3436             :              * Release locks prior to commit. XXX There is a race condition
    3437             :              * here that may allow backends to reconnect, but the window for
    3438             :              * this is small because the gap between here and commit is mostly
    3439             :              * fairly small and it is unlikely that people will be dropping
    3440             :              * databases that we are trying to connect to anyway.
    3441             :              */
    3442          28 :             UnlockSharedObjectForSession(DatabaseRelationId, xlrec->db_id, 0, AccessExclusiveLock);
    3443             :         }
    3444             :     }
    3445             :     else
    3446           0 :         elog(PANIC, "dbase_redo: unknown op code %u", info);
    3447          84 : }

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