LCOV - code coverage report
Current view: top level - src/backend/catalog - toasting.c (source / functions) Hit Total Coverage
Test: PostgreSQL 18devel Lines: 117 123 95.1 %
Date: 2024-11-21 09:14:53 Functions: 7 7 100.0 %
Legend: Lines: hit not hit

          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) 1996-2024, 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/toasting.h"
      30             : #include "miscadmin.h"
      31             : #include "nodes/makefuncs.h"
      32             : #include "utils/fmgroids.h"
      33             : #include "utils/rel.h"
      34             : #include "utils/syscache.h"
      35             : 
      36             : static void CheckAndCreateToastTable(Oid relOid, Datum reloptions,
      37             :                                      LOCKMODE lockmode, bool check,
      38             :                                      Oid OIDOldToast);
      39             : static bool create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
      40             :                                Datum reloptions, LOCKMODE lockmode, bool check,
      41             :                                Oid OIDOldToast);
      42             : static bool needs_toast_table(Relation rel);
      43             : 
      44             : 
      45             : /*
      46             :  * CreateToastTable variants
      47             :  *      If the table needs a toast table, and doesn't already have one,
      48             :  *      then create a toast table for it.
      49             :  *
      50             :  * reloptions for the toast table can be passed, too.  Pass (Datum) 0
      51             :  * for default reloptions.
      52             :  *
      53             :  * We expect the caller to have verified that the relation is a table and have
      54             :  * already done any necessary permission checks.  Callers expect this function
      55             :  * to end with CommandCounterIncrement if it makes any changes.
      56             :  */
      57             : void
      58       26226 : AlterTableCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode)
      59             : {
      60       26226 :     CheckAndCreateToastTable(relOid, reloptions, lockmode, true, InvalidOid);
      61       26226 : }
      62             : 
      63             : void
      64         836 : NewHeapCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
      65             :                         Oid OIDOldToast)
      66             : {
      67         836 :     CheckAndCreateToastTable(relOid, reloptions, lockmode, false, OIDOldToast);
      68         836 : }
      69             : 
      70             : void
      71       35426 : NewRelationCreateToastTable(Oid relOid, Datum reloptions)
      72             : {
      73       35426 :     CheckAndCreateToastTable(relOid, reloptions, AccessExclusiveLock, false,
      74             :                              InvalidOid);
      75       35426 : }
      76             : 
      77             : static void
      78       62488 : CheckAndCreateToastTable(Oid relOid, Datum reloptions, LOCKMODE lockmode,
      79             :                          bool check, Oid OIDOldToast)
      80             : {
      81             :     Relation    rel;
      82             : 
      83       62488 :     rel = table_open(relOid, lockmode);
      84             : 
      85             :     /* create_toast_table does all the work */
      86       62488 :     (void) create_toast_table(rel, InvalidOid, InvalidOid, reloptions, lockmode,
      87             :                               check, OIDOldToast);
      88             : 
      89       62488 :     table_close(rel, NoLock);
      90       62488 : }
      91             : 
      92             : /*
      93             :  * Create a toast table during bootstrap
      94             :  *
      95             :  * Here we need to prespecify the OIDs of the toast table and its index
      96             :  */
      97             : void
      98        3240 : BootstrapToastTable(char *relName, Oid toastOid, Oid toastIndexOid)
      99             : {
     100             :     Relation    rel;
     101             : 
     102        3240 :     rel = table_openrv(makeRangeVar(NULL, relName, -1), AccessExclusiveLock);
     103             : 
     104        3240 :     if (rel->rd_rel->relkind != RELKIND_RELATION &&
     105           0 :         rel->rd_rel->relkind != RELKIND_MATVIEW)
     106           0 :         elog(ERROR, "\"%s\" is not a table or materialized view",
     107             :              relName);
     108             : 
     109             :     /* create_toast_table does all the work */
     110        3240 :     if (!create_toast_table(rel, toastOid, toastIndexOid, (Datum) 0,
     111             :                             AccessExclusiveLock, false, InvalidOid))
     112           0 :         elog(ERROR, "\"%s\" does not require a toast table",
     113             :              relName);
     114             : 
     115        3240 :     table_close(rel, NoLock);
     116        3240 : }
     117             : 
     118             : 
     119             : /*
     120             :  * create_toast_table --- internal workhorse
     121             :  *
     122             :  * rel is already opened and locked
     123             :  * toastOid and toastIndexOid are normally InvalidOid, but during
     124             :  * bootstrap they can be nonzero to specify hand-assigned OIDs
     125             :  */
     126             : static bool
     127       65728 : create_toast_table(Relation rel, Oid toastOid, Oid toastIndexOid,
     128             :                    Datum reloptions, LOCKMODE lockmode, bool check,
     129             :                    Oid OIDOldToast)
     130             : {
     131       65728 :     Oid         relOid = RelationGetRelid(rel);
     132             :     HeapTuple   reltup;
     133             :     TupleDesc   tupdesc;
     134             :     bool        shared_relation;
     135             :     bool        mapped_relation;
     136             :     Relation    toast_rel;
     137             :     Relation    class_rel;
     138             :     Oid         toast_relid;
     139             :     Oid         namespaceid;
     140             :     char        toast_relname[NAMEDATALEN];
     141             :     char        toast_idxname[NAMEDATALEN];
     142             :     IndexInfo  *indexInfo;
     143             :     Oid         collationIds[2];
     144             :     Oid         opclassIds[2];
     145             :     int16       coloptions[2];
     146             :     ObjectAddress baseobject,
     147             :                 toastobject;
     148             : 
     149             :     /*
     150             :      * Is it already toasted?
     151             :      */
     152       65728 :     if (rel->rd_rel->reltoastrelid != InvalidOid)
     153        9904 :         return false;
     154             : 
     155             :     /*
     156             :      * Check to see whether the table actually needs a TOAST table.
     157             :      */
     158       55824 :     if (!IsBinaryUpgrade)
     159             :     {
     160             :         /* Normal mode, normal check */
     161       52866 :         if (!needs_toast_table(rel))
     162       36792 :             return false;
     163             :     }
     164             :     else
     165             :     {
     166             :         /*
     167             :          * In binary-upgrade mode, create a TOAST table if and only if
     168             :          * pg_upgrade told us to (ie, a TOAST table OID has been provided).
     169             :          *
     170             :          * This indicates that the old cluster had a TOAST table for the
     171             :          * current table.  We must create a TOAST table to receive the old
     172             :          * TOAST file, even if the table seems not to need one.
     173             :          *
     174             :          * Contrariwise, if the old cluster did not have a TOAST table, we
     175             :          * should be able to get along without one even if the new version's
     176             :          * needs_toast_table rules suggest we should have one.  There is a lot
     177             :          * of daylight between where we will create a TOAST table and where
     178             :          * one is really necessary to avoid failures, so small cross-version
     179             :          * differences in the when-to-create heuristic shouldn't be a problem.
     180             :          * If we tried to create a TOAST table anyway, we would have the
     181             :          * problem that it might take up an OID that will conflict with some
     182             :          * old-cluster table we haven't seen yet.
     183             :          */
     184        2958 :         if (!OidIsValid(binary_upgrade_next_toast_pg_class_oid))
     185        2430 :             return false;
     186             :     }
     187             : 
     188             :     /*
     189             :      * If requested check lockmode is sufficient. This is a cross check in
     190             :      * case of errors or conflicting decisions in earlier code.
     191             :      */
     192       16602 :     if (check && lockmode != AccessExclusiveLock)
     193           0 :         elog(ERROR, "AccessExclusiveLock required to add toast table.");
     194             : 
     195             :     /*
     196             :      * Create the toast table and its index
     197             :      */
     198       16602 :     snprintf(toast_relname, sizeof(toast_relname),
     199             :              "pg_toast_%u", relOid);
     200       16602 :     snprintf(toast_idxname, sizeof(toast_idxname),
     201             :              "pg_toast_%u_index", relOid);
     202             : 
     203             :     /* this is pretty painful...  need a tuple descriptor */
     204       16602 :     tupdesc = CreateTemplateTupleDesc(3);
     205       16602 :     TupleDescInitEntry(tupdesc, (AttrNumber) 1,
     206             :                        "chunk_id",
     207             :                        OIDOID,
     208             :                        -1, 0);
     209       16602 :     TupleDescInitEntry(tupdesc, (AttrNumber) 2,
     210             :                        "chunk_seq",
     211             :                        INT4OID,
     212             :                        -1, 0);
     213       16602 :     TupleDescInitEntry(tupdesc, (AttrNumber) 3,
     214             :                        "chunk_data",
     215             :                        BYTEAOID,
     216             :                        -1, 0);
     217             : 
     218             :     /*
     219             :      * Ensure that the toast table doesn't itself get toasted, or we'll be
     220             :      * toast :-(.  This is essential for chunk_data because type bytea is
     221             :      * toastable; hit the other two just to be sure.
     222             :      */
     223       16602 :     TupleDescAttr(tupdesc, 0)->attstorage = TYPSTORAGE_PLAIN;
     224       16602 :     TupleDescAttr(tupdesc, 1)->attstorage = TYPSTORAGE_PLAIN;
     225       16602 :     TupleDescAttr(tupdesc, 2)->attstorage = TYPSTORAGE_PLAIN;
     226             : 
     227             :     /* Toast field should not be compressed */
     228       16602 :     TupleDescAttr(tupdesc, 0)->attcompression = InvalidCompressionMethod;
     229       16602 :     TupleDescAttr(tupdesc, 1)->attcompression = InvalidCompressionMethod;
     230       16602 :     TupleDescAttr(tupdesc, 2)->attcompression = InvalidCompressionMethod;
     231             : 
     232             :     /*
     233             :      * Toast tables for regular relations go in pg_toast; those for temp
     234             :      * relations go into the per-backend temp-toast-table namespace.
     235             :      */
     236       16602 :     if (isTempOrTempToastNamespace(rel->rd_rel->relnamespace))
     237         916 :         namespaceid = GetTempToastNamespace();
     238             :     else
     239       15686 :         namespaceid = PG_TOAST_NAMESPACE;
     240             : 
     241             :     /* Toast table is shared if and only if its parent is. */
     242       16602 :     shared_relation = rel->rd_rel->relisshared;
     243             : 
     244             :     /* It's mapped if and only if its parent is, too */
     245       16602 :     mapped_relation = RelationIsMapped(rel);
     246             : 
     247       33204 :     toast_relid = heap_create_with_catalog(toast_relname,
     248             :                                            namespaceid,
     249       16602 :                                            rel->rd_rel->reltablespace,
     250             :                                            toastOid,
     251             :                                            InvalidOid,
     252             :                                            InvalidOid,
     253       16602 :                                            rel->rd_rel->relowner,
     254             :                                            table_relation_toast_am(rel),
     255             :                                            tupdesc,
     256             :                                            NIL,
     257             :                                            RELKIND_TOASTVALUE,
     258       16602 :                                            rel->rd_rel->relpersistence,
     259             :                                            shared_relation,
     260             :                                            mapped_relation,
     261             :                                            ONCOMMIT_NOOP,
     262             :                                            reloptions,
     263             :                                            false,
     264             :                                            true,
     265             :                                            true,
     266             :                                            OIDOldToast,
     267             :                                            NULL);
     268             :     Assert(toast_relid != InvalidOid);
     269             : 
     270             :     /* make the toast relation visible, else table_open will fail */
     271       16602 :     CommandCounterIncrement();
     272             : 
     273             :     /* ShareLock is not really needed here, but take it anyway */
     274       16602 :     toast_rel = table_open(toast_relid, ShareLock);
     275             : 
     276             :     /*
     277             :      * Create unique index on chunk_id, chunk_seq.
     278             :      *
     279             :      * NOTE: the normal TOAST access routines could actually function with a
     280             :      * single-column index on chunk_id only. However, the slice access
     281             :      * routines use both columns for faster access to an individual chunk. In
     282             :      * addition, we want it to be unique as a check against the possibility of
     283             :      * duplicate TOAST chunk OIDs. The index might also be a little more
     284             :      * efficient this way, since btree isn't all that happy with large numbers
     285             :      * of equal keys.
     286             :      */
     287             : 
     288       16602 :     indexInfo = makeNode(IndexInfo);
     289       16602 :     indexInfo->ii_NumIndexAttrs = 2;
     290       16602 :     indexInfo->ii_NumIndexKeyAttrs = 2;
     291       16602 :     indexInfo->ii_IndexAttrNumbers[0] = 1;
     292       16602 :     indexInfo->ii_IndexAttrNumbers[1] = 2;
     293       16602 :     indexInfo->ii_Expressions = NIL;
     294       16602 :     indexInfo->ii_ExpressionsState = NIL;
     295       16602 :     indexInfo->ii_Predicate = NIL;
     296       16602 :     indexInfo->ii_PredicateState = NULL;
     297       16602 :     indexInfo->ii_ExclusionOps = NULL;
     298       16602 :     indexInfo->ii_ExclusionProcs = NULL;
     299       16602 :     indexInfo->ii_ExclusionStrats = NULL;
     300       16602 :     indexInfo->ii_Unique = true;
     301       16602 :     indexInfo->ii_NullsNotDistinct = false;
     302       16602 :     indexInfo->ii_ReadyForInserts = true;
     303       16602 :     indexInfo->ii_CheckedUnchanged = false;
     304       16602 :     indexInfo->ii_IndexUnchanged = false;
     305       16602 :     indexInfo->ii_Concurrent = false;
     306       16602 :     indexInfo->ii_BrokenHotChain = false;
     307       16602 :     indexInfo->ii_ParallelWorkers = 0;
     308       16602 :     indexInfo->ii_Am = BTREE_AM_OID;
     309       16602 :     indexInfo->ii_AmCache = NULL;
     310       16602 :     indexInfo->ii_Context = CurrentMemoryContext;
     311             : 
     312       16602 :     collationIds[0] = InvalidOid;
     313       16602 :     collationIds[1] = InvalidOid;
     314             : 
     315       16602 :     opclassIds[0] = OID_BTREE_OPS_OID;
     316       16602 :     opclassIds[1] = INT4_BTREE_OPS_OID;
     317             : 
     318       16602 :     coloptions[0] = 0;
     319       16602 :     coloptions[1] = 0;
     320             : 
     321       16602 :     index_create(toast_rel, toast_idxname, toastIndexOid, InvalidOid,
     322             :                  InvalidOid, InvalidOid,
     323             :                  indexInfo,
     324       16602 :                  list_make2("chunk_id", "chunk_seq"),
     325             :                  BTREE_AM_OID,
     326       16602 :                  rel->rd_rel->reltablespace,
     327             :                  collationIds, opclassIds, NULL, coloptions, NULL, (Datum) 0,
     328             :                  INDEX_CREATE_IS_PRIMARY, 0, true, true, NULL);
     329             : 
     330       16602 :     table_close(toast_rel, NoLock);
     331             : 
     332             :     /*
     333             :      * Store the toast table's OID in the parent relation's pg_class row
     334             :      */
     335       16602 :     class_rel = table_open(RelationRelationId, RowExclusiveLock);
     336             : 
     337       16602 :     if (!IsBootstrapProcessingMode())
     338             :     {
     339             :         /* normal case, use a transactional update */
     340       13362 :         reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relOid));
     341       13362 :         if (!HeapTupleIsValid(reltup))
     342           0 :             elog(ERROR, "cache lookup failed for relation %u", relOid);
     343             : 
     344       13362 :         ((Form_pg_class) GETSTRUCT(reltup))->reltoastrelid = toast_relid;
     345             : 
     346       13362 :         CatalogTupleUpdate(class_rel, &reltup->t_self, reltup);
     347             :     }
     348             :     else
     349             :     {
     350             :         /* While bootstrapping, we cannot UPDATE, so overwrite in-place */
     351             : 
     352             :         ScanKeyData key[1];
     353             :         void       *state;
     354             : 
     355        3240 :         ScanKeyInit(&key[0],
     356             :                     Anum_pg_class_oid,
     357             :                     BTEqualStrategyNumber, F_OIDEQ,
     358             :                     ObjectIdGetDatum(relOid));
     359        3240 :         systable_inplace_update_begin(class_rel, ClassOidIndexId, true,
     360             :                                       NULL, 1, key, &reltup, &state);
     361        3240 :         if (!HeapTupleIsValid(reltup))
     362           0 :             elog(ERROR, "cache lookup failed for relation %u", relOid);
     363             : 
     364        3240 :         ((Form_pg_class) GETSTRUCT(reltup))->reltoastrelid = toast_relid;
     365             : 
     366        3240 :         systable_inplace_update_finish(state, reltup);
     367             :     }
     368             : 
     369       16602 :     heap_freetuple(reltup);
     370             : 
     371       16602 :     table_close(class_rel, RowExclusiveLock);
     372             : 
     373             :     /*
     374             :      * Register dependency from the toast table to the main, so that the toast
     375             :      * table will be deleted if the main is.  Skip this in bootstrap mode.
     376             :      */
     377       16602 :     if (!IsBootstrapProcessingMode())
     378             :     {
     379       13362 :         baseobject.classId = RelationRelationId;
     380       13362 :         baseobject.objectId = relOid;
     381       13362 :         baseobject.objectSubId = 0;
     382       13362 :         toastobject.classId = RelationRelationId;
     383       13362 :         toastobject.objectId = toast_relid;
     384       13362 :         toastobject.objectSubId = 0;
     385             : 
     386       13362 :         recordDependencyOn(&toastobject, &baseobject, DEPENDENCY_INTERNAL);
     387             :     }
     388             : 
     389             :     /*
     390             :      * Make changes visible
     391             :      */
     392       16602 :     CommandCounterIncrement();
     393             : 
     394       16602 :     return true;
     395             : }
     396             : 
     397             : /*
     398             :  * Check to see whether the table needs a TOAST table.
     399             :  */
     400             : static bool
     401       52866 : needs_toast_table(Relation rel)
     402             : {
     403             :     /*
     404             :      * No need to create a TOAST table for partitioned tables.
     405             :      */
     406       52866 :     if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
     407        7696 :         return false;
     408             : 
     409             :     /*
     410             :      * We cannot allow toasting a shared relation after initdb (because
     411             :      * there's no way to mark it toasted in other databases' pg_class).
     412             :      */
     413       45170 :     if (rel->rd_rel->relisshared && !IsBootstrapProcessingMode())
     414         430 :         return false;
     415             : 
     416             :     /*
     417             :      * Ignore attempts to create toast tables on catalog tables after initdb.
     418             :      * Which catalogs get toast tables is explicitly chosen in catalog/pg_*.h.
     419             :      * (We could get here via some ALTER TABLE command if the catalog doesn't
     420             :      * have a toast table.)
     421             :      */
     422       44740 :     if (IsCatalogRelation(rel) && !IsBootstrapProcessingMode())
     423        3870 :         return false;
     424             : 
     425             :     /* Otherwise, let the AM decide. */
     426       40870 :     return table_relation_needs_toast_table(rel);
     427             : }

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