Line data    Source code

       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * toasting.c
       4             :  *    This file contains routines to support creation of toast tables
       5             :  *
       6             :  *
       7             :  * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
       8             :  * Portions Copyright (c) 1994, Regents of the University of California
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/catalog/toasting.c
      12             :  *
      13             :  *-------------------------------------------------------------------------
      14             :  */
      15             : #include "postgres.h"
      16             : 
      17             : #include "access/heapam.h"
      18             : #include "access/toast_compression.h"
      19             : #include "access/xact.h"
      20             : #include "catalog/binary_upgrade.h"
      21             : #include "catalog/catalog.h"
      22             : #include "catalog/dependency.h"
      23             : #include "catalog/heap.h"
      24             : #include "catalog/index.h"
      25             : #include "catalog/namespace.h"
      26             : #include "catalog/pg_am.h"
      27             : #include "catalog/pg_namespace.h"
      28             : #include "catalog/pg_opclass.h"
      29             : #include "catalog/pg_type.h"
      30             : #include "catalog/toasting.h"
      31             : #include "miscadmin.h"
      32             : #include "nodes/makefuncs.h"
      33             : #include "storage/lock.h"
      34             : #include "utils/builtins.h"
      35             : #include "utils/rel.h"
      36             : #include "utils/syscache.h"
      37             : 
      38             : static void CheckAndCreateToastTable(Oid relOid, Datum reloptions,
      39             :                                      LOCKMODE lockmode, bool check,
      40             :                                      Oid OIDOldToast);
      41             : static bool create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
      42             :                                Datum reloptions, LOCKMODE lockmode, bool check,
      43             :                                Oid OIDOldToast);
      44             : static bool needs_toast_table(Relation rel);
      45             : 
      46             : 
      47             : /*
      48             :  * CreateToastTable variants
      49             :  *      If the table needs a toast table, and doesn't already have one,
      50             :  *      then create a toast table for it.
      51             :  *
      52             :  * reloptions for the toast table can be passed, too.  Pass (Datum) 0
      53             :  * for default reloptions.
      54             :  *
      55             :  * We expect the caller to have verified that the relation is a table and have
      56             :  * already done any necessary permission checks.  Callers expect this function
      57             :  * to end with CommandCounterIncrement if it makes any changes.
      58             :  */
      59             : void
      60       28104 : AlterTableCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode)
      61             : {
      62       28104 :     CheckAndCreateToastTable(relOid, reloptions, lockmode, true, InvalidOid);
      63       28104 : }
      64             : 
      65             : void
      66         602 : NewHeapCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
      67             :                         Oid OIDOldToast)
      68             : {
      69         602 :     CheckAndCreateToastTable(relOid, reloptions, lockmode, false, OIDOldToast);
      70         602 : }
      71             : 
      72             : void
      73       33198 : NewRelationCreateToastTable(Oid relOid, Datum reloptions)
      74             : {
      75       33198 :     CheckAndCreateToastTable(relOid, reloptions, AccessExclusiveLock, false,
      76             :                              InvalidOid);
      77       33198 : }
      78             : 
      79             : static void
      80       61904 : CheckAndCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
      81             :                          bool check, Oid OIDOldToast)
      82             : {
      83             :     Relation    rel;
      84             : 
      85       61904 :     rel = table_open(relOid, lockmode);
      86             : 
      87             :     /* create_toast_table does all the work */
      88       61904 :     (void) create_toast_table(rel, InvalidOid, InvalidOid, reloptions, lockmode,
      89             :                               check, OIDOldToast);
      90             : 
      91       61904 :     table_close(rel, NoLock);
      92       61904 : }
      93             : 
      94             : /*
      95             :  * Create a toast table during bootstrap
      96             :  *
      97             :  * Here we need to prespecify the OIDs of the toast table and its index
      98             :  */
      99             : void
     100        2304 : BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid)
     101             : {
     102             :     Relation    rel;
     103             : 
     104        2304 :     rel = table_openrv(makeRangeVar(NULL, relName, -1), AccessExclusiveLock);
     105             : 
     106        2304 :     if (rel->rd_rel->relkind != RELKIND_RELATION &&
     107           0 :         rel->rd_rel->relkind != RELKIND_MATVIEW)
     108           0 :         elog(ERROR, "\"%s\" is not a table or materialized view",
     109             :              relName);
     110             : 
     111             :     /* create_toast_table does all the work */
     112        2304 :     if (!create_toast_table(rel, toastOid, toastIndexOid, (Datum) 0,
     113             :                             AccessExclusiveLock, false, InvalidOid))
     114           0 :         elog(ERROR, "\"%s\" does not require a toast table",
     115             :              relName);
     116             : 
     117        2304 :     table_close(rel, NoLock);
     118        2304 : }
     119             : 
     120             : 
     121             : /*
     122             :  * create_toast_table --- internal workhorse
     123             :  *
     124             :  * rel is already opened and locked
     125             :  * toastOid and toastIndexOid are normally InvalidOid, but during
     126             :  * bootstrap they can be nonzero to specify hand-assigned OIDs
     127             :  */
     128             : static bool
     129       64208 : create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
     130             :                    Datum reloptions, LOCKMODE lockmode, bool check,
     131             :                    Oid OIDOldToast)
     132             : {
     133       64208 :     Oid         relOid = RelationGetRelid(rel);
     134             :     HeapTuple   reltup;
     135             :     TupleDesc   tupdesc;
     136             :     bool        shared_relation;
     137             :     bool        mapped_relation;
     138             :     Relation    toast_rel;
     139             :     Relation    class_rel;
     140             :     Oid         toast_relid;
     141             :     Oid         namespaceid;
     142             :     char        toast_relname[NAMEDATALEN];
     143             :     char        toast_idxname[NAMEDATALEN];
     144             :     IndexInfo  *indexInfo;
     145             :     Oid         collationIds[2];
     146             :     Oid         opclassIds[2];
     147             :     int16       coloptions[2];
     148             :     ObjectAddress baseobject,
     149             :                 toastobject;
     150             : 
     151             :     /*
     152             :      * Is it already toasted?
     153             :      */
     154       64208 :     if (rel->rd_rel->reltoastrelid != InvalidOid)
     155       10198 :         return false;
     156             : 
     157             :     /*
     158             :      * Check to see whether the table actually needs a TOAST table.
     159             :      */
     160       54010 :     if (!IsBinaryUpgrade)
     161             :     {
     162             :         /* Normal mode, normal check */
     163       50966 :         if (!needs_toast_table(rel))
     164       37246 :             return false;
     165             :     }
     166             :     else
     167             :     {
     168             :         /*
     169             :          * In binary-upgrade mode, create a TOAST table if and only if
     170             :          * pg_upgrade told us to (ie, a TOAST table OID has been provided).
     171             :          *
     172             :          * This indicates that the old cluster had a TOAST table for the
     173             :          * current table.  We must create a TOAST table to receive the old
     174             :          * TOAST file, even if the table seems not to need one.
     175             :          *
     176             :          * Contrariwise, if the old cluster did not have a TOAST table, we
     177             :          * should be able to get along without one even if the new version's
     178             :          * needs_toast_table rules suggest we should have one.  There is a lot
     179             :          * of daylight between where we will create a TOAST table and where
     180             :          * one is really necessary to avoid failures, so small cross-version
     181             :          * differences in the when-to-create heuristic shouldn't be a problem.
     182             :          * If we tried to create a TOAST table anyway, we would have the
     183             :          * problem that it might take up an OID that will conflict with some
     184             :          * old-cluster table we haven't seen yet.
     185             :          */
     186        3044 :         if (!OidIsValid(binary_upgrade_next_toast_pg_class_oid))
     187        2554 :             return false;
     188             :     }
     189             : 
     190             :     /*
     191             :      * If requested check lockmode is sufficient. This is a cross check in
     192             :      * case of errors or conflicting decisions in earlier code.
     193             :      */
     194       14210 :     if (check && lockmode != AccessExclusiveLock)
     195           0 :         elog(ERROR, "AccessExclusiveLock required to add toast table.");
     196             : 
     197             :     /*
     198             :      * Create the toast table and its index
     199             :      */
     200       14210 :     snprintf(toast_relname, sizeof(toast_relname),
     201             :              "pg_toast_%u", relOid);
     202       14210 :     snprintf(toast_idxname, sizeof(toast_idxname),
     203             :              "pg_toast_%u_index", relOid);
     204             : 
     205             :     /* this is pretty painful...  need a tuple descriptor */
     206       14210 :     tupdesc = CreateTemplateTupleDesc(3);
     207       14210 :     TupleDescInitEntry(tupdesc, (AttrNumber) 1,
     208             :                        "chunk_id",
     209             :                        OIDOID,
     210             :                        -1, 0);
     211       14210 :     TupleDescInitEntry(tupdesc, (AttrNumber) 2,
     212             :                        "chunk_seq",
     213             :                        INT4OID,
     214             :                        -1, 0);
     215       14210 :     TupleDescInitEntry(tupdesc, (AttrNumber) 3,
     216             :                        "chunk_data",
     217             :                        BYTEAOID,
     218             :                        -1, 0);
     219             : 
     220             :     /*
     221             :      * Ensure that the toast table doesn't itself get toasted, or we'll be
     222             :      * toast :-(.  This is essential for chunk_data because type bytea is
     223             :      * toastable; hit the other two just to be sure.
     224             :      */
     225       14210 :     TupleDescAttr(tupdesc, 0)->attstorage = TYPSTORAGE_PLAIN;
     226       14210 :     TupleDescAttr(tupdesc, 1)->attstorage = TYPSTORAGE_PLAIN;
     227       14210 :     TupleDescAttr(tupdesc, 2)->attstorage = TYPSTORAGE_PLAIN;
     228             : 
     229             :     /* Toast field should not be compressed */
     230       14210 :     TupleDescAttr(tupdesc, 0)->attcompression = InvalidCompressionMethod;
     231       14210 :     TupleDescAttr(tupdesc, 1)->attcompression = InvalidCompressionMethod;
     232       14210 :     TupleDescAttr(tupdesc, 2)->attcompression = InvalidCompressionMethod;
     233             : 
     234             :     /*
     235             :      * Toast tables for regular relations go in pg_toast; those for temp
     236             :      * relations go into the per-backend temp-toast-table namespace.
     237             :      */
     238       14210 :     if (isTempOrTempToastNamespace(rel->rd_rel->relnamespace))
     239         860 :         namespaceid = GetTempToastNamespace();
     240             :     else
     241       13350 :         namespaceid = PG_TOAST_NAMESPACE;
     242             : 
     243             :     /* Toast table is shared if and only if its parent is. */
     244       14210 :     shared_relation = rel->rd_rel->relisshared;
     245             : 
     246             :     /* It's mapped if and only if its parent is, too */
     247       14210 :     mapped_relation = RelationIsMapped(rel);
     248             : 
     249       28420 :     toast_relid = heap_create_with_catalog(toast_relname,
     250             :                                            namespaceid,
     251       14210 :                                            rel->rd_rel->reltablespace,
     252             :                                            toastOid,
     253             :                                            InvalidOid,
     254             :                                            InvalidOid,
     255       14210 :                                            rel->rd_rel->relowner,
     256             :                                            table_relation_toast_am(rel),
     257             :                                            tupdesc,
     258             :                                            NIL,
     259             :                                            RELKIND_TOASTVALUE,
     260       14210 :                                            rel->rd_rel->relpersistence,
     261             :                                            shared_relation,
     262             :                                            mapped_relation,
     263             :                                            ONCOMMIT_NOOP,
     264             :                                            reloptions,
     265             :                                            false,
     266             :                                            true,
     267             :                                            true,
     268             :                                            OIDOldToast,
     269             :                                            NULL);
     270             :     Assert(toast_relid != InvalidOid);
     271             : 
     272             :     /* make the toast relation visible, else table_open will fail */
     273       14210 :     CommandCounterIncrement();
     274             : 
     275             :     /* ShareLock is not really needed here, but take it anyway */
     276       14210 :     toast_rel = table_open(toast_relid, ShareLock);
     277             : 
     278             :     /*
     279             :      * Create unique index on chunk_id, chunk_seq.
     280             :      *
     281             :      * NOTE: the normal TOAST access routines could actually function with a
     282             :      * single-column index on chunk_id only. However, the slice access
     283             :      * routines use both columns for faster access to an individual chunk. In
     284             :      * addition, we want it to be unique as a check against the possibility of
     285             :      * duplicate TOAST chunk OIDs. The index might also be a little more
     286             :      * efficient this way, since btree isn't all that happy with large numbers
     287             :      * of equal keys.
     288             :      */
     289             : 
     290       14210 :     indexInfo = makeNode(IndexInfo);
     291       14210 :     indexInfo->ii_NumIndexAttrs = 2;
     292       14210 :     indexInfo->ii_NumIndexKeyAttrs = 2;
     293       14210 :     indexInfo->ii_IndexAttrNumbers[0] = 1;
     294       14210 :     indexInfo->ii_IndexAttrNumbers[1] = 2;
     295       14210 :     indexInfo->ii_Expressions = NIL;
     296       14210 :     indexInfo->ii_ExpressionsState = NIL;
     297       14210 :     indexInfo->ii_Predicate = NIL;
     298       14210 :     indexInfo->ii_PredicateState = NULL;
     299       14210 :     indexInfo->ii_ExclusionOps = NULL;
     300       14210 :     indexInfo->ii_ExclusionProcs = NULL;
     301       14210 :     indexInfo->ii_ExclusionStrats = NULL;
     302       14210 :     indexInfo->ii_Unique = true;
     303       14210 :     indexInfo->ii_NullsNotDistinct = false;
     304       14210 :     indexInfo->ii_ReadyForInserts = true;
     305       14210 :     indexInfo->ii_CheckedUnchanged = false;
     306       14210 :     indexInfo->ii_IndexUnchanged = false;
     307       14210 :     indexInfo->ii_Concurrent = false;
     308       14210 :     indexInfo->ii_BrokenHotChain = false;
     309       14210 :     indexInfo->ii_ParallelWorkers = 0;
     310       14210 :     indexInfo->ii_Am = BTREE_AM_OID;
     311       14210 :     indexInfo->ii_AmCache = NULL;
     312       14210 :     indexInfo->ii_Context = CurrentMemoryContext;
     313             : 
     314       14210 :     collationIds[0] = InvalidOid;
     315       14210 :     collationIds[1] = InvalidOid;
     316             : 
     317       14210 :     opclassIds[0] = OID_BTREE_OPS_OID;
     318       14210 :     opclassIds[1] = INT4_BTREE_OPS_OID;
     319             : 
     320       14210 :     coloptions[0] = 0;
     321       14210 :     coloptions[1] = 0;
     322             : 
     323       14210 :     index_create(toast_rel, toast_idxname, toastIndexOid, InvalidOid,
     324             :                  InvalidOid, InvalidOid,
     325             :                  indexInfo,
     326       14210 :                  list_make2("chunk_id", "chunk_seq"),
     327             :                  BTREE_AM_OID,
     328       14210 :                  rel->rd_rel->reltablespace,
     329             :                  collationIds, opclassIds, NULL, coloptions, (Datum) 0,
     330             :                  INDEX_CREATE_IS_PRIMARY, 0, true, true, NULL);
     331             : 
     332       14210 :     table_close(toast_rel, NoLock);
     333             : 
     334             :     /*
     335             :      * Store the toast table's OID in the parent relation's pg_class row
     336             :      */
     337       14210 :     class_rel = table_open(RelationRelationId, RowExclusiveLock);
     338             : 
     339       14210 :     reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relOid));
     340       14210 :     if (!HeapTupleIsValid(reltup))
     341           0 :         elog(ERROR, "cache lookup failed for relation %u", relOid);
     342             : 
     343       14210 :     ((Form_pg_class) GETSTRUCT(reltup))->reltoastrelid = toast_relid;
     344             : 
     345       14210 :     if (!IsBootstrapProcessingMode())
     346             :     {
     347             :         /* normal case, use a transactional update */
     348       11906 :         CatalogTupleUpdate(class_rel, &reltup->t_self, reltup);
     349             :     }
     350             :     else
     351             :     {
     352             :         /* While bootstrapping, we cannot UPDATE, so overwrite in-place */
     353        2304 :         heap_inplace_update(class_rel, reltup);
     354             :     }
     355             : 
     356       14210 :     heap_freetuple(reltup);
     357             : 
     358       14210 :     table_close(class_rel, RowExclusiveLock);
     359             : 
     360             :     /*
     361             :      * Register dependency from the toast table to the main, so that the toast
     362             :      * table will be deleted if the main is.  Skip this in bootstrap mode.
     363             :      */
     364       14210 :     if (!IsBootstrapProcessingMode())
     365             :     {
     366       11906 :         baseobject.classId = RelationRelationId;
     367       11906 :         baseobject.objectId = relOid;
     368       11906 :         baseobject.objectSubId = 0;
     369       11906 :         toastobject.classId = RelationRelationId;
     370       11906 :         toastobject.objectId = toast_relid;
     371       11906 :         toastobject.objectSubId = 0;
     372             : 
     373       11906 :         recordDependencyOn(&toastobject, &baseobject, DEPENDENCY_INTERNAL);
     374             :     }
     375             : 
     376             :     /*
     377             :      * Make changes visible
     378             :      */
     379       14210 :     CommandCounterIncrement();
     380             : 
     381       14210 :     return true;
     382             : }
     383             : 
     384             : /*
     385             :  * Check to see whether the table needs a TOAST table.
     386             :  */
     387             : static bool
     388       50966 : needs_toast_table(Relation rel)
     389             : {
     390             :     /*
     391             :      * No need to create a TOAST table for partitioned tables.
     392             :      */
     393       50966 :     if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
     394        7680 :         return false;
     395             : 
     396             :     /*
     397             :      * We cannot allow toasting a shared relation after initdb (because
     398             :      * there's no way to mark it toasted in other databases' pg_class).
     399             :      */
     400       43286 :     if (rel->rd_rel->relisshared && !IsBootstrapProcessingMode())
     401         180 :         return false;
     402             : 
     403             :     /*
     404             :      * Ignore attempts to create toast tables on catalog tables after initdb.
     405             :      * Which catalogs get toast tables is explicitly chosen in catalog/pg_*.h.
     406             :      * (We could get here via some ALTER TABLE command if the catalog doesn't
     407             :      * have a toast table.)
     408             :      */
     409       43106 :     if (IsCatalogRelation(rel) && !IsBootstrapProcessingMode())
     410        2760 :         return false;
     411             : 
     412             :     /* Otherwise, let the AM decide. */
     413       40346 :     return table_relation_needs_toast_table(rel);
     414             : }