indexcmds.c

来自「PostgreSQL7.4.6 for Linux」· C语言 代码 · 共 777 行 · 第 1/2 页

										  accessMethodId);
		attn++;
	}
}

/*
 * Resolve possibly-defaulted operator class specification
 */
static Oid
GetIndexOpClass(List *opclass, Oid attrType,
				char *accessMethodName, Oid accessMethodId)
{
	char	   *schemaname;
	char	   *opcname;
	HeapTuple	tuple;
	Oid			opClassId,
				opInputType;

	/*
	 * Release 7.0 removed network_ops, timespan_ops, and datetime_ops, so
	 * we ignore those opclass names so the default *_ops is used.	This
	 * can be removed in some later release.  bjm 2000/02/07
	 *
	 * Release 7.1 removes lztext_ops, so suppress that too for a while.  tgl
	 * 2000/07/30
	 *
	 * Release 7.2 renames timestamp_ops to timestamptz_ops, so suppress that
	 * too for awhile.	I'm starting to think we need a better approach.
	 * tgl 2000/10/01
	 */
	if (length(opclass) == 1)
	{
		char	   *claname = strVal(lfirst(opclass));

		if (strcmp(claname, "network_ops") == 0 ||
			strcmp(claname, "timespan_ops") == 0 ||
			strcmp(claname, "datetime_ops") == 0 ||
			strcmp(claname, "lztext_ops") == 0 ||
			strcmp(claname, "timestamp_ops") == 0)
			opclass = NIL;
	}

	if (opclass == NIL)
	{
		/* no operator class specified, so find the default */
		opClassId = GetDefaultOpClass(attrType, accessMethodId);
		if (!OidIsValid(opClassId))
			ereport(ERROR,
					(errcode(ERRCODE_UNDEFINED_OBJECT),
					 errmsg("data type %s has no default operator class for access method \"%s\"",
							format_type_be(attrType), accessMethodName),
					 errhint("You must specify an operator class for the index or define a default operator class for the data type.")));
		return opClassId;
	}

	/*
	 * Specific opclass name given, so look up the opclass.
	 */

	/* deconstruct the name list */
	DeconstructQualifiedName(opclass, &schemaname, &opcname);

	if (schemaname)
	{
		/* Look in specific schema only */
		Oid			namespaceId;

		namespaceId = LookupExplicitNamespace(schemaname);
		tuple = SearchSysCache(CLAAMNAMENSP,
							   ObjectIdGetDatum(accessMethodId),
							   PointerGetDatum(opcname),
							   ObjectIdGetDatum(namespaceId),
							   0);
	}
	else
	{
		/* Unqualified opclass name, so search the search path */
		opClassId = OpclassnameGetOpcid(accessMethodId, opcname);
		if (!OidIsValid(opClassId))
			ereport(ERROR,
					(errcode(ERRCODE_UNDEFINED_OBJECT),
					 errmsg("operator class \"%s\" does not exist for access method \"%s\"",
							opcname, accessMethodName)));
		tuple = SearchSysCache(CLAOID,
							   ObjectIdGetDatum(opClassId),
							   0, 0, 0);
	}

	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("operator class \"%s\" does not exist for access method \"%s\"",
						NameListToString(opclass), accessMethodName)));

	/*
	 * Verify that the index operator class accepts this datatype.	Note
	 * we will accept binary compatibility.
	 */
	opClassId = HeapTupleGetOid(tuple);
	opInputType = ((Form_pg_opclass) GETSTRUCT(tuple))->opcintype;

	if (!IsBinaryCoercible(attrType, opInputType))
		ereport(ERROR,
				(errcode(ERRCODE_DATATYPE_MISMATCH),
			 errmsg("operator class \"%s\" does not accept data type %s",
				  NameListToString(opclass), format_type_be(attrType))));

	ReleaseSysCache(tuple);

	return opClassId;
}

static Oid
GetDefaultOpClass(Oid attrType, Oid accessMethodId)
{
	OpclassCandidateList opclass;
	int			nexact = 0;
	int			ncompatible = 0;
	Oid			exactOid = InvalidOid;
	Oid			compatibleOid = InvalidOid;

	/* If it's a domain, look at the base type instead */
	attrType = getBaseType(attrType);

	/*
	 * We scan through all the opclasses available for the access method,
	 * looking for one that is marked default and matches the target type
	 * (either exactly or binary-compatibly, but prefer an exact match).
	 *
	 * We could find more than one binary-compatible match, in which case we
	 * require the user to specify which one he wants.	If we find more
	 * than one exact match, then someone put bogus entries in pg_opclass.
	 *
	 * The initial search is done by namespace.c so that we only consider
	 * opclasses visible in the current namespace search path.  (See also
	 * typcache.c, which applies the same logic, but over all opclasses.)
	 */
	for (opclass = OpclassGetCandidates(accessMethodId);
		 opclass != NULL;
		 opclass = opclass->next)
	{
		if (opclass->opcdefault)
		{
			if (opclass->opcintype == attrType)
			{
				nexact++;
				exactOid = opclass->oid;
			}
			else if (IsBinaryCoercible(attrType, opclass->opcintype))
			{
				ncompatible++;
				compatibleOid = opclass->oid;
			}
		}
	}

	if (nexact == 1)
		return exactOid;
	if (nexact != 0)
		ereport(ERROR,
				(errcode(ERRCODE_DUPLICATE_OBJECT),
				 errmsg("there are multiple default operator classes for data type %s",
						format_type_be(attrType))));
	if (ncompatible == 1)
		return compatibleOid;

	return InvalidOid;
}

/*
 * RemoveIndex
 *		Deletes an index.
 */
void
RemoveIndex(RangeVar *relation, DropBehavior behavior)
{
	Oid			indOid;
	char		relkind;
	ObjectAddress object;

	indOid = RangeVarGetRelid(relation, false);
	relkind = get_rel_relkind(indOid);
	if (relkind != RELKIND_INDEX)
		ereport(ERROR,
				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
				 errmsg("\"%s\" is not an index",
						relation->relname)));

	object.classId = RelOid_pg_class;
	object.objectId = indOid;
	object.objectSubId = 0;

	performDeletion(&object, behavior);
}

/*
 * ReindexIndex
 *		Recreate an index.
 */
void
ReindexIndex(RangeVar *indexRelation, bool force /* currently unused */ )
{
	Oid			indOid;
	HeapTuple	tuple;

	indOid = RangeVarGetRelid(indexRelation, false);
	tuple = SearchSysCache(RELOID,
						   ObjectIdGetDatum(indOid),
						   0, 0, 0);
	if (!HeapTupleIsValid(tuple))		/* shouldn't happen */
		elog(ERROR, "cache lookup failed for relation %u", indOid);

	if (((Form_pg_class) GETSTRUCT(tuple))->relkind != RELKIND_INDEX)
		ereport(ERROR,
				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
				 errmsg("\"%s\" is not an index",
						indexRelation->relname)));

	/* Check permissions */
	if (!pg_class_ownercheck(indOid, GetUserId()))
		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
					   indexRelation->relname);

	ReleaseSysCache(tuple);

	reindex_index(indOid);
}

/*
 * ReindexTable
 *		Recreate indexes of a table.
 */
void
ReindexTable(RangeVar *relation, bool force /* currently unused */ )
{
	Oid			heapOid;
	HeapTuple	tuple;

	heapOid = RangeVarGetRelid(relation, false);
	tuple = SearchSysCache(RELOID,
						   ObjectIdGetDatum(heapOid),
						   0, 0, 0);
	if (!HeapTupleIsValid(tuple))		/* shouldn't happen */
		elog(ERROR, "cache lookup failed for relation %u", heapOid);

	if (((Form_pg_class) GETSTRUCT(tuple))->relkind != RELKIND_RELATION &&
		((Form_pg_class) GETSTRUCT(tuple))->relkind != RELKIND_TOASTVALUE)
		ereport(ERROR,
				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
				 errmsg("\"%s\" is not a table",
						relation->relname)));

	/* Check permissions */
	if (!pg_class_ownercheck(heapOid, GetUserId()))
		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
					   relation->relname);

	/* Can't reindex shared tables except in standalone mode */
	if (((Form_pg_class) GETSTRUCT(tuple))->relisshared && IsUnderPostmaster)
		ereport(ERROR,
				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
				 errmsg("shared table \"%s\" can only be reindexed in stand-alone mode",
						relation->relname)));

	ReleaseSysCache(tuple);

	if (!reindex_relation(heapOid))
		ereport(NOTICE,
				(errmsg("table \"%s\" has no indexes",
						relation->relname)));
}

/*
 * ReindexDatabase
 *		Recreate indexes of a database.
 *
 * To reduce the probability of deadlocks, each table is reindexed in a
 * separate transaction, so we can release the lock on it right away.
 */
void
ReindexDatabase(const char *dbname, bool force /* currently unused */,
				bool all)
{
	Relation	relationRelation;
	HeapScanDesc scan;
	HeapTuple	tuple;
	MemoryContext private_context;
	MemoryContext old;
	List	   *relids = NIL;

	AssertArg(dbname);

	if (strcmp(dbname, get_database_name(MyDatabaseId)) != 0)
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("can only reindex the currently open database")));

	if (!pg_database_ownercheck(MyDatabaseId, GetUserId()))
		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_DATABASE,
					   dbname);

	/*
	 * We cannot run inside a user transaction block; if we were inside a
	 * transaction, then our commit- and start-transaction-command calls
	 * would not have the intended effect!
	 */
	PreventTransactionChain((void *) dbname, "REINDEX DATABASE");

	/*
	 * Create a memory context that will survive forced transaction
	 * commits we do below.  Since it is a child of PortalContext, it will
	 * go away eventually even if we suffer an error; there's no need for
	 * special abort cleanup logic.
	 */
	private_context = AllocSetContextCreate(PortalContext,
											"ReindexDatabase",
											ALLOCSET_DEFAULT_MINSIZE,
											ALLOCSET_DEFAULT_INITSIZE,
											ALLOCSET_DEFAULT_MAXSIZE);

	/*
	 * We always want to reindex pg_class first.  This ensures that if
	 * there is any corruption in pg_class' indexes, they will be fixed
	 * before we process any other tables.  This is critical because
	 * reindexing itself will try to update pg_class.
	 */
	old = MemoryContextSwitchTo(private_context);
	relids = lappendo(relids, RelOid_pg_class);
	MemoryContextSwitchTo(old);

	/*
	 * Scan pg_class to build a list of the relations we need to reindex.
	 *
	 * We only consider plain relations here (toast rels will be processed
	 * indirectly by reindex_relation).
	 */
	relationRelation = heap_openr(RelationRelationName, AccessShareLock);
	scan = heap_beginscan(relationRelation, SnapshotNow, 0, NULL);
	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
	{
		Form_pg_class classtuple = (Form_pg_class) GETSTRUCT(tuple);

		if (classtuple->relkind != RELKIND_RELATION)
			continue;

		if (!all)				/* only system tables? */
		{
			if (!IsSystemClass(classtuple))
				continue;
		}

		if (IsUnderPostmaster)	/* silently ignore shared tables */
		{
			if (classtuple->relisshared)
				continue;
		}

		if (HeapTupleGetOid(tuple) == RelOid_pg_class)
			continue;			/* got it already */

		old = MemoryContextSwitchTo(private_context);
		relids = lappendo(relids, HeapTupleGetOid(tuple));
		MemoryContextSwitchTo(old);
	}
	heap_endscan(scan);
	heap_close(relationRelation, AccessShareLock);

	/* Now reindex each rel in a separate transaction */
	CommitTransactionCommand();
	while (relids)
	{
		Oid		relid = lfirsto(relids);

		StartTransactionCommand();
		SetQuerySnapshot();		/* might be needed for functions in
								 * indexes */
		if (reindex_relation(relid))
			ereport(NOTICE,
					(errmsg("table \"%s\" was reindexed",
							get_rel_name(relid))));
		CommitTransactionCommand();
		relids = lnext(relids);
	}
	StartTransactionCommand();

	MemoryContextDelete(private_context);
}