granicus.if.org Git - postgresql/blob - src/backend/commands/indexcmds.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * indexcmds.c
   4  *        POSTGRES define and remove index code.
   5  *
   6  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
   7  * Portions Copyright (c) 1994, Regents of the University of California
   8  *
   9  *
  10  * IDENTIFICATION
  11  *        $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.79 2002/07/29 23:46:35 tgl Exp $
  12  *
  13  *-------------------------------------------------------------------------
  14  */
  15
  16 #include "postgres.h"
  17
  18 #include "access/heapam.h"
  19 #include "catalog/catalog.h"
  20 #include "catalog/catname.h"
  21 #include "catalog/dependency.h"
  22 #include "catalog/index.h"
  23 #include "catalog/namespace.h"
  24 #include "catalog/pg_opclass.h"
  25 #include "catalog/pg_proc.h"
  26 #include "commands/defrem.h"
  27 #include "miscadmin.h"
  28 #include "optimizer/clauses.h"
  29 #include "optimizer/planmain.h"
  30 #include "optimizer/prep.h"
  31 #include "parser/parsetree.h"
  32 #include "parser/parse_coerce.h"
  33 #include "parser/parse_func.h"
  34 #include "utils/acl.h"
  35 #include "utils/builtins.h"
  36 #include "utils/lsyscache.h"
  37 #include "utils/syscache.h"
  38
  39
  40 #define IsFuncIndex(ATTR_LIST) (((IndexElem*)lfirst(ATTR_LIST))->funcname != NIL)
  41
  42 /* non-export function prototypes */
  43 static void CheckPredicate(List *predList, List *rangeTable, Oid baseRelOid);
  44 static void FuncIndexArgs(IndexInfo *indexInfo, Oid *classOidP,
  45                           IndexElem *funcIndex,
  46                           Oid relId,
  47                           char *accessMethodName, Oid accessMethodId);
  48 static void NormIndexAttrs(IndexInfo *indexInfo, Oid *classOidP,
  49                            List *attList,
  50                            Oid relId,
  51                            char *accessMethodName, Oid accessMethodId);
  52 static Oid GetAttrOpClass(IndexElem *attribute, Oid attrType,
  53                            char *accessMethodName, Oid accessMethodId);
  54 static Oid      GetDefaultOpClass(Oid attrType, Oid accessMethodId);
  55
  56 /*
  57  * DefineIndex
  58  *              Creates a new index.
  59  *
  60  * 'attributeList' is a list of IndexElem specifying either a functional
  61  *              index or a list of attributes to index on.
  62  * 'predicate' is the qual specified in the where clause.
  63  * 'rangetable' is needed to interpret the predicate.
  64  */
  65 void
  66 DefineIndex(RangeVar *heapRelation,
  67                         char *indexRelationName,
  68                         char *accessMethodName,
  69                         List *attributeList,
  70                         bool unique,
  71                         bool primary,
  72                         bool isconstraint,
  73                         Expr *predicate,
  74                         List *rangetable)
  75 {
  76         Oid                *classObjectId;
  77         Oid                     accessMethodId;
  78         Oid                     relationId;
  79         Oid                     namespaceId;
  80         Relation        rel;
  81         HeapTuple       tuple;
  82         Form_pg_am      accessMethodForm;
  83         IndexInfo  *indexInfo;
  84         int                     numberOfAttributes;
  85         List       *cnfPred = NIL;
  86
  87         /*
  88          * count attributes in index
  89          */
  90         numberOfAttributes = length(attributeList);
  91         if (numberOfAttributes <= 0)
  92                 elog(ERROR, "DefineIndex: must specify at least one attribute");
  93         if (numberOfAttributes > INDEX_MAX_KEYS)
  94                 elog(ERROR, "Cannot use more than %d attributes in an index",
  95                          INDEX_MAX_KEYS);
  96
  97         /*
  98          * Open heap relation, acquire a suitable lock on it, remember its OID
  99          */
 100         rel = heap_openrv(heapRelation, ShareLock);
 101
 102         /* Note: during bootstrap may see uncataloged relation */
 103         if (rel->rd_rel->relkind != RELKIND_RELATION &&
 104                 rel->rd_rel->relkind != RELKIND_UNCATALOGED)
 105                 elog(ERROR, "DefineIndex: relation \"%s\" is not a table",
 106                          heapRelation->relname);
 107
 108         relationId = RelationGetRelid(rel);
 109         namespaceId = RelationGetNamespace(rel);
 110
 111         if (!IsBootstrapProcessingMode() &&
 112                 IsSystemRelation(rel) &&
 113                 !IndexesAreActive(relationId, false))
 114                 elog(ERROR, "Existing indexes are inactive. REINDEX first");
 115
 116         heap_close(rel, NoLock);
 117
 118         /*
 119          * Verify we (still) have CREATE rights in the rel's namespace.
 120          * (Presumably we did when the rel was created, but maybe not anymore.)
 121          * Skip check if bootstrapping, since permissions machinery may not
 122          * be working yet; also, always allow if it's a temp table.
 123          */
 124         if (!IsBootstrapProcessingMode() && !isTempNamespace(namespaceId))
 125         {
 126                 AclResult       aclresult;
 127
 128                 aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
 129                                                                                   ACL_CREATE);
 130                 if (aclresult != ACLCHECK_OK)
 131                         aclcheck_error(aclresult, get_namespace_name(namespaceId));
 132         }
 133
 134         /*
 135          * look up the access method, verify it can handle the requested
 136          * features
 137          */
 138         tuple = SearchSysCache(AMNAME,
 139                                                    PointerGetDatum(accessMethodName),
 140                                                    0, 0, 0);
 141         if (!HeapTupleIsValid(tuple))
 142                 elog(ERROR, "DefineIndex: access method \"%s\" not found",
 143                          accessMethodName);
 144         accessMethodId = HeapTupleGetOid(tuple);
 145         accessMethodForm = (Form_pg_am) GETSTRUCT(tuple);
 146
 147         if (unique && !accessMethodForm->amcanunique)
 148                 elog(ERROR, "DefineIndex: access method \"%s\" does not support UNIQUE indexes",
 149                          accessMethodName);
 150         if (numberOfAttributes > 1 && !accessMethodForm->amcanmulticol)
 151                 elog(ERROR, "DefineIndex: access method \"%s\" does not support multi-column indexes",
 152                          accessMethodName);
 153
 154         ReleaseSysCache(tuple);
 155
 156         /*
 157          * Convert the partial-index predicate from parsetree form to an
 158          * implicit-AND qual expression, for easier evaluation at runtime.
 159          * While we are at it, we reduce it to a canonical (CNF or DNF) form
 160          * to simplify the task of proving implications.
 161          */
 162         if (predicate != NULL && rangetable != NIL)
 163         {
 164                 cnfPred = canonicalize_qual((Expr *) copyObject(predicate), true);
 165                 fix_opids((Node *) cnfPred);
 166                 CheckPredicate(cnfPred, rangetable, relationId);
 167         }
 168
 169         /*
 170          * Prepare arguments for index_create, primarily an IndexInfo
 171          * structure
 172          */
 173         indexInfo = makeNode(IndexInfo);
 174         indexInfo->ii_Predicate = cnfPred;
 175         indexInfo->ii_FuncOid = InvalidOid;
 176         indexInfo->ii_Unique = unique;
 177
 178         if (IsFuncIndex(attributeList))
 179         {
 180                 IndexElem  *funcIndex = (IndexElem *) lfirst(attributeList);
 181                 int                     nargs;
 182
 183                 /* Parser should have given us only one list item, but check */
 184                 if (numberOfAttributes != 1)
 185                         elog(ERROR, "Functional index can only have one attribute");
 186
 187                 nargs = length(funcIndex->args);
 188                 if (nargs > INDEX_MAX_KEYS)
 189                         elog(ERROR, "Index function can take at most %d arguments",
 190                                  INDEX_MAX_KEYS);
 191
 192                 indexInfo->ii_NumIndexAttrs = 1;
 193                 indexInfo->ii_NumKeyAttrs = nargs;
 194
 195                 classObjectId = (Oid *) palloc(sizeof(Oid));
 196
 197                 FuncIndexArgs(indexInfo, classObjectId, funcIndex,
 198                                           relationId, accessMethodName, accessMethodId);
 199         }
 200         else
 201         {
 202                 indexInfo->ii_NumIndexAttrs = numberOfAttributes;
 203                 indexInfo->ii_NumKeyAttrs = numberOfAttributes;
 204
 205                 classObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
 206
 207                 NormIndexAttrs(indexInfo, classObjectId, attributeList,
 208                                            relationId, accessMethodName, accessMethodId);
 209         }
 210
 211         index_create(relationId, indexRelationName,
 212                                  indexInfo, accessMethodId, classObjectId,
 213                                  primary, isconstraint, allowSystemTableMods);
 214
 215         /*
 216          * We update the relation's pg_class tuple even if it already has
 217          * relhasindex = true.  This is needed to cause a shared-cache-inval
 218          * message to be sent for the pg_class tuple, which will cause other
 219          * backends to flush their relcache entries and in particular their
 220          * cached lists of the indexes for this relation.
 221          */
 222         setRelhasindex(relationId, true, primary, InvalidOid);
 223 }
 224
 225
 226 /*
 227  * CheckPredicate
 228  *              Checks that the given list of partial-index predicates refer
 229  *              (via the given range table) only to the given base relation oid.
 230  *
 231  * This used to also constrain the form of the predicate to forms that
 232  * indxpath.c could do something with.  However, that seems overly
 233  * restrictive.  One useful application of partial indexes is to apply
 234  * a UNIQUE constraint across a subset of a table, and in that scenario
 235  * any evaluatable predicate will work.  So accept any predicate here
 236  * (except ones requiring a plan), and let indxpath.c fend for itself.
 237  */
 238
 239 static void
 240 CheckPredicate(List *predList, List *rangeTable, Oid baseRelOid)
 241 {
 242         if (length(rangeTable) != 1 || getrelid(1, rangeTable) != baseRelOid)
 243                 elog(ERROR,
 244                  "Partial-index predicates may refer only to the base relation");
 245
 246         /*
 247          * We don't currently support generation of an actual query plan for a
 248          * predicate, only simple scalar expressions; hence these
 249          * restrictions.
 250          */
 251         if (contain_subplans((Node *) predList))
 252                 elog(ERROR, "Cannot use subselect in index predicate");
 253         if (contain_agg_clause((Node *) predList))
 254                 elog(ERROR, "Cannot use aggregate in index predicate");
 255
 256         /*
 257          * A predicate using mutable functions is probably wrong, for the
 258          * same reasons that we don't allow a functional index to use one.
 259          */
 260         if (contain_mutable_functions((Node *) predList))
 261                 elog(ERROR, "Functions in index predicate must be marked isImmutable");
 262 }
 263
 264
 265 static void
 266 FuncIndexArgs(IndexInfo *indexInfo,
 267                           Oid *classOidP,
 268                           IndexElem *funcIndex,
 269                           Oid relId,
 270                           char *accessMethodName,
 271                           Oid accessMethodId)
 272 {
 273         Oid                     argTypes[FUNC_MAX_ARGS];
 274         List       *arglist;
 275         int                     nargs = 0;
 276         int                     i;
 277         FuncDetailCode fdresult;
 278         Oid                     funcid;
 279         Oid                     rettype;
 280         bool            retset;
 281         Oid                *true_typeids;
 282
 283         /*
 284          * process the function arguments, which are a list of T_String
 285          * (someday ought to allow more general expressions?)
 286          *
 287          * Note caller already checked that list is not too long.
 288          */
 289         MemSet(argTypes, 0, sizeof(argTypes));
 290
 291         foreach(arglist, funcIndex->args)
 292         {
 293                 char       *arg = strVal(lfirst(arglist));
 294                 HeapTuple       tuple;
 295                 Form_pg_attribute att;
 296
 297                 tuple = SearchSysCache(ATTNAME,
 298                                                            ObjectIdGetDatum(relId),
 299                                                            PointerGetDatum(arg),
 300                                                            0, 0);
 301                 if (!HeapTupleIsValid(tuple))
 302                         elog(ERROR, "DefineIndex: attribute \"%s\" not found", arg);
 303                 att = (Form_pg_attribute) GETSTRUCT(tuple);
 304                 indexInfo->ii_KeyAttrNumbers[nargs] = att->attnum;
 305                 argTypes[nargs] = att->atttypid;
 306                 ReleaseSysCache(tuple);
 307                 nargs++;
 308         }
 309
 310         /*
 311          * Lookup the function procedure to get its OID and result type.
 312          *
 313          * We rely on parse_func.c to find the correct function in the possible
 314          * presence of binary-compatible types.  However, parse_func may do
 315          * too much: it will accept a function that requires run-time coercion
 316          * of input types, and the executor is not currently set up to support
 317          * that.  So, check to make sure that the selected function has
 318          * exact-match or binary-compatible input types.
 319          */
 320         fdresult = func_get_detail(funcIndex->funcname, funcIndex->args,
 321                                                            nargs, argTypes,
 322                                                            &funcid, &rettype, &retset,
 323                                                            &true_typeids);
 324         if (fdresult != FUNCDETAIL_NORMAL)
 325         {
 326                 if (fdresult == FUNCDETAIL_AGGREGATE)
 327                         elog(ERROR, "DefineIndex: functional index may not use an aggregate function");
 328                 else if (fdresult == FUNCDETAIL_COERCION)
 329                         elog(ERROR, "DefineIndex: functional index must use a real function, not a type coercion"
 330                                  "\n\tTry specifying the index opclass you want to use, instead");
 331                 else
 332                         func_error("DefineIndex", funcIndex->funcname, nargs, argTypes,
 333                                            NULL);
 334         }
 335
 336         if (retset)
 337                 elog(ERROR, "DefineIndex: cannot index on a function returning a set");
 338
 339         for (i = 0; i < nargs; i++)
 340         {
 341                 if (!IsBinaryCompatible(argTypes[i], true_typeids[i]))
 342                         func_error("DefineIndex", funcIndex->funcname, nargs, argTypes,
 343                                            "Index function must be binary-compatible with table datatype");
 344         }
 345
 346         /*
 347          * Require that the function be marked immutable.  Using a mutable
 348          * function for a functional index is highly questionable, since if
 349          * you aren't going to get the same result for the same data every
 350          * time, it's not clear what the index entries mean at all.
 351          */
 352         if (func_volatile(funcid) != PROVOLATILE_IMMUTABLE)
 353                 elog(ERROR, "DefineIndex: index function must be marked isImmutable");
 354
 355         /* Process opclass, using func return type as default type */
 356
 357         classOidP[0] = GetAttrOpClass(funcIndex, rettype,
 358                                                                   accessMethodName, accessMethodId);
 359
 360         /* OK, return results */
 361
 362         indexInfo->ii_FuncOid = funcid;
 363         /* Need to do the fmgr function lookup now, too */
 364         fmgr_info(funcid, &indexInfo->ii_FuncInfo);
 365 }
 366
 367 static void
 368 NormIndexAttrs(IndexInfo *indexInfo,
 369                            Oid *classOidP,
 370                            List *attList,       /* list of IndexElem's */
 371                            Oid relId,
 372                            char *accessMethodName,
 373                            Oid accessMethodId)
 374 {
 375         List       *rest;
 376         int                     attn = 0;
 377
 378         /*
 379          * process attributeList
 380          */
 381         foreach(rest, attList)
 382         {
 383                 IndexElem  *attribute = (IndexElem *) lfirst(rest);
 384                 HeapTuple       atttuple;
 385                 Form_pg_attribute attform;
 386
 387                 if (attribute->name == NULL)
 388                         elog(ERROR, "missing attribute for define index");
 389
 390                 atttuple = SearchSysCache(ATTNAME,
 391                                                                   ObjectIdGetDatum(relId),
 392                                                                   PointerGetDatum(attribute->name),
 393                                                                   0, 0);
 394                 if (!HeapTupleIsValid(atttuple))
 395                         elog(ERROR, "DefineIndex: attribute \"%s\" not found",
 396                                  attribute->name);
 397                 attform = (Form_pg_attribute) GETSTRUCT(atttuple);
 398
 399                 indexInfo->ii_KeyAttrNumbers[attn] = attform->attnum;
 400
 401                 classOidP[attn] = GetAttrOpClass(attribute, attform->atttypid,
 402                                                                            accessMethodName, accessMethodId);
 403
 404                 ReleaseSysCache(atttuple);
 405                 attn++;
 406         }
 407 }
 408
 409 static Oid
 410 GetAttrOpClass(IndexElem *attribute, Oid attrType,
 411                            char *accessMethodName, Oid accessMethodId)
 412 {
 413         char       *schemaname;
 414         char       *opcname;
 415         HeapTuple       tuple;
 416         Oid                     opClassId,
 417                                 opInputType;
 418
 419         if (attribute->opclass == NIL)
 420         {
 421                 /* no operator class specified, so find the default */
 422                 opClassId = GetDefaultOpClass(attrType, accessMethodId);
 423                 if (!OidIsValid(opClassId))
 424                         elog(ERROR, "data type %s has no default operator class for access method \"%s\""
 425                                  "\n\tYou must specify an operator class for the index or define a"
 426                                  "\n\tdefault operator class for the data type",
 427                                  format_type_be(attrType), accessMethodName);
 428                 return opClassId;
 429         }
 430
 431         /*
 432          * Specific opclass name given, so look up the opclass.
 433          */
 434
 435         /* deconstruct the name list */
 436         DeconstructQualifiedName(attribute->opclass, &schemaname, &opcname);
 437
 438         if (schemaname)
 439         {
 440                 /* Look in specific schema only */
 441                 Oid             namespaceId;
 442
 443                 namespaceId = LookupExplicitNamespace(schemaname);
 444                 tuple = SearchSysCache(CLAAMNAMENSP,
 445                                                            ObjectIdGetDatum(accessMethodId),
 446                                                            PointerGetDatum(opcname),
 447                                                            ObjectIdGetDatum(namespaceId),
 448                                                            0);
 449         }
 450         else
 451         {
 452                 /* Unqualified opclass name, so search the search path */
 453                 opClassId = OpclassnameGetOpcid(accessMethodId, opcname);
 454                 if (!OidIsValid(opClassId))
 455                         elog(ERROR, "DefineIndex: operator class \"%s\" not supported by access method \"%s\"",
 456                                  opcname, accessMethodName);
 457                 tuple = SearchSysCache(CLAOID,
 458                                                            ObjectIdGetDatum(opClassId),
 459                                                            0, 0, 0);
 460         }
 461
 462         if (!HeapTupleIsValid(tuple))
 463                 elog(ERROR, "DefineIndex: operator class \"%s\" not supported by access method \"%s\"",
 464                          NameListToString(attribute->opclass), accessMethodName);
 465
 466         /*
 467          * Verify that the index operator class accepts this
 468          * datatype.  Note we will accept binary compatibility.
 469          */
 470         opClassId = HeapTupleGetOid(tuple);
 471         opInputType = ((Form_pg_opclass) GETSTRUCT(tuple))->opcintype;
 472
 473         if (!IsBinaryCompatible(attrType, opInputType))
 474                 elog(ERROR, "operator class \"%s\" does not accept data type %s",
 475                          NameListToString(attribute->opclass), format_type_be(attrType));
 476
 477         ReleaseSysCache(tuple);
 478
 479         return opClassId;
 480 }
 481
 482 static Oid
 483 GetDefaultOpClass(Oid attrType, Oid accessMethodId)
 484 {
 485         OpclassCandidateList opclass;
 486         int                     nexact = 0;
 487         int                     ncompatible = 0;
 488         Oid                     exactOid = InvalidOid;
 489         Oid                     compatibleOid = InvalidOid;
 490
 491         /*
 492          * We scan through all the opclasses available for the access method,
 493          * looking for one that is marked default and matches the target type
 494          * (either exactly or binary-compatibly, but prefer an exact match).
 495          *
 496          * We could find more than one binary-compatible match, in which case we
 497          * require the user to specify which one he wants.      If we find more
 498          * than one exact match, then someone put bogus entries in pg_opclass.
 499          *
 500          * The initial search is done by namespace.c so that we only consider
 501          * opclasses visible in the current namespace search path.
 502          */
 503         for (opclass = OpclassGetCandidates(accessMethodId);
 504                  opclass != NULL;
 505                  opclass = opclass->next)
 506         {
 507                 if (opclass->opcdefault)
 508                 {
 509                         if (opclass->opcintype == attrType)
 510                         {
 511                                 nexact++;
 512                                 exactOid = opclass->oid;
 513                         }
 514                         else if (IsBinaryCompatible(opclass->opcintype, attrType))
 515                         {
 516                                 ncompatible++;
 517                                 compatibleOid = opclass->oid;
 518                         }
 519                 }
 520         }
 521
 522         if (nexact == 1)
 523                 return exactOid;
 524         if (nexact != 0)
 525                 elog(ERROR, "pg_opclass contains multiple default opclasses for data type %s",
 526                          format_type_be(attrType));
 527         if (ncompatible == 1)
 528                 return compatibleOid;
 529
 530         return InvalidOid;
 531 }
 532
 533 /*
 534  * RemoveIndex
 535  *              Deletes an index.
 536  */
 537 void
 538 RemoveIndex(RangeVar *relation, DropBehavior behavior)
 539 {
 540         Oid                     indOid;
 541         HeapTuple       tuple;
 542         ObjectAddress object;
 543
 544         indOid = RangeVarGetRelid(relation, false);
 545         tuple = SearchSysCache(RELOID,
 546                                                    ObjectIdGetDatum(indOid),
 547                                                    0, 0, 0);
 548         if (!HeapTupleIsValid(tuple))
 549                 elog(ERROR, "index \"%s\" does not exist", relation->relname);
 550
 551         if (((Form_pg_class) GETSTRUCT(tuple))->relkind != RELKIND_INDEX)
 552                 elog(ERROR, "relation \"%s\" is of type \"%c\"",
 553                          relation->relname, ((Form_pg_class) GETSTRUCT(tuple))->relkind);
 554
 555         ReleaseSysCache(tuple);
 556
 557         object.classId = RelOid_pg_class;
 558         object.objectId = indOid;
 559         object.objectSubId = 0;
 560
 561         performDeletion(&object, behavior);
 562 }
 563
 564 /*
 565  * Reindex
 566  *              Recreate an index.
 567  *
 568  * Exceptions:
 569  *              "ERROR" if index nonexistent.
 570  *              ...
 571  */
 572 void
 573 ReindexIndex(RangeVar *indexRelation, bool force /* currently unused */ )
 574 {
 575         Oid                     indOid;
 576         HeapTuple       tuple;
 577         bool            overwrite = false;
 578
 579         /*
 580          * REINDEX within a transaction block is dangerous, because if the
 581          * transaction is later rolled back we have no way to undo truncation
 582          * of the index's physical file.  Disallow it.
 583          */
 584         if (IsTransactionBlock())
 585                 elog(ERROR, "REINDEX cannot run inside a BEGIN/END block");
 586
 587         indOid = RangeVarGetRelid(indexRelation, false);
 588         tuple = SearchSysCache(RELOID,
 589                                                    ObjectIdGetDatum(indOid),
 590                                                    0, 0, 0);
 591         if (!HeapTupleIsValid(tuple))
 592                 elog(ERROR, "index \"%s\" does not exist", indexRelation->relname);
 593
 594         if (((Form_pg_class) GETSTRUCT(tuple))->relkind != RELKIND_INDEX)
 595                 elog(ERROR, "relation \"%s\" is of type \"%c\"",
 596                          indexRelation->relname,
 597                          ((Form_pg_class) GETSTRUCT(tuple))->relkind);
 598
 599         if (IsSystemClass((Form_pg_class) GETSTRUCT(tuple)))
 600         {
 601                 if (!allowSystemTableMods)
 602                         elog(ERROR, "\"%s\" is a system index. call REINDEX under standalone postgres with -O -P options",
 603                                  indexRelation->relname);
 604                 if (!IsIgnoringSystemIndexes())
 605                         elog(ERROR, "\"%s\" is a system index. call REINDEX under standalone postgres with -P -O options",
 606                                  indexRelation->relname);
 607         }
 608
 609         ReleaseSysCache(tuple);
 610
 611         if (IsIgnoringSystemIndexes())
 612                 overwrite = true;
 613         if (!reindex_index(indOid, force, overwrite))
 614                 elog(WARNING, "index \"%s\" wasn't reindexed", indexRelation->relname);
 615 }
 616
 617 /*
 618  * ReindexTable
 619  *              Recreate indexes of a table.
 620  *
 621  * Exceptions:
 622  *              "ERROR" if table nonexistent.
 623  *              ...
 624  */
 625 void
 626 ReindexTable(RangeVar *relation, bool force)
 627 {
 628         Oid                     heapOid;
 629         HeapTuple       tuple;
 630
 631         /*
 632          * REINDEX within a transaction block is dangerous, because if the
 633          * transaction is later rolled back we have no way to undo truncation
 634          * of the index's physical file.  Disallow it.
 635          */
 636         if (IsTransactionBlock())
 637                 elog(ERROR, "REINDEX cannot run inside a BEGIN/END block");
 638
 639         heapOid = RangeVarGetRelid(relation, false);
 640         tuple = SearchSysCache(RELOID,
 641                                                    ObjectIdGetDatum(heapOid),
 642                                                    0, 0, 0);
 643         if (!HeapTupleIsValid(tuple))
 644                 elog(ERROR, "table \"%s\" does not exist", relation->relname);
 645
 646         if (((Form_pg_class) GETSTRUCT(tuple))->relkind != RELKIND_RELATION)
 647                 elog(ERROR, "relation \"%s\" is of type \"%c\"",
 648                          relation->relname,
 649                          ((Form_pg_class) GETSTRUCT(tuple))->relkind);
 650
 651         ReleaseSysCache(tuple);
 652
 653         if (!reindex_relation(heapOid, force))
 654                 elog(WARNING, "table \"%s\" wasn't reindexed", relation->relname);
 655 }
 656
 657 /*
 658  * ReindexDatabase
 659  *              Recreate indexes of a database.
 660  */
 661 void
 662 ReindexDatabase(const char *dbname, bool force, bool all)
 663 {
 664         Relation        relationRelation;
 665         HeapScanDesc scan;
 666         HeapTuple       tuple;
 667         MemoryContext private_context;
 668         MemoryContext old;
 669         int                     relcnt,
 670                                 relalc,
 671                                 i,
 672                                 oncealc = 200;
 673         Oid                *relids = (Oid *) NULL;
 674
 675         AssertArg(dbname);
 676
 677         if (strcmp(dbname, DatabaseName) != 0)
 678                 elog(ERROR, "REINDEX DATABASE: Can be executed only on the currently open database.");
 679
 680         if (!(superuser() || is_dbadmin(MyDatabaseId)))
 681                 elog(ERROR, "REINDEX DATABASE: Permission denied.");
 682
 683         if (!allowSystemTableMods)
 684                 elog(ERROR, "must be called under standalone postgres with -O -P options");
 685         if (!IsIgnoringSystemIndexes())
 686                 elog(ERROR, "must be called under standalone postgres with -P -O options");
 687
 688         /*
 689          * We cannot run inside a user transaction block; if we were inside a
 690          * transaction, then our commit- and start-transaction-command calls
 691          * would not have the intended effect!
 692          */
 693         if (IsTransactionBlock())
 694                 elog(ERROR, "REINDEX DATABASE cannot run inside a BEGIN/END block");
 695
 696         /*
 697          * Create a memory context that will survive forced transaction
 698          * commits we do below.  Since it is a child of QueryContext, it will
 699          * go away eventually even if we suffer an error; there's no need for
 700          * special abort cleanup logic.
 701          */
 702         private_context = AllocSetContextCreate(QueryContext,
 703                                                                                         "ReindexDatabase",
 704                                                                                         ALLOCSET_DEFAULT_MINSIZE,
 705                                                                                         ALLOCSET_DEFAULT_INITSIZE,
 706                                                                                         ALLOCSET_DEFAULT_MAXSIZE);
 707
 708         /*
 709          * Scan pg_class to build a list of the relations we need to reindex.
 710          */
 711         relationRelation = heap_openr(RelationRelationName, AccessShareLock);
 712         scan = heap_beginscan(relationRelation, SnapshotNow, 0, NULL);
 713         relcnt = relalc = 0;
 714         while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 715         {
 716                 if (!all)
 717                 {
 718                         if (!IsSystemClass((Form_pg_class) GETSTRUCT(tuple)))
 719                                 continue;
 720                 }
 721                 if (((Form_pg_class) GETSTRUCT(tuple))->relkind == RELKIND_RELATION)
 722                 {
 723                         old = MemoryContextSwitchTo(private_context);
 724                         if (relcnt == 0)
 725                         {
 726                                 relalc = oncealc;
 727                                 relids = palloc(sizeof(Oid) * relalc);
 728                         }
 729                         else if (relcnt >= relalc)
 730                         {
 731                                 relalc *= 2;
 732                                 relids = repalloc(relids, sizeof(Oid) * relalc);
 733                         }
 734                         MemoryContextSwitchTo(old);
 735                         relids[relcnt] = HeapTupleGetOid(tuple);
 736                         relcnt++;
 737                 }
 738         }
 739         heap_endscan(scan);
 740         heap_close(relationRelation, AccessShareLock);
 741
 742         /* Now reindex each rel in a separate transaction */
 743         CommitTransactionCommand();
 744         for (i = 0; i < relcnt; i++)
 745         {
 746                 StartTransactionCommand();
 747                 if (reindex_relation(relids[i], force))
 748                         elog(WARNING, "relation %u was reindexed", relids[i]);
 749                 CommitTransactionCommand();
 750         }
 751         StartTransactionCommand();
 752
 753         MemoryContextDelete(private_context);
 754 }