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b084cc3504
to behave according to SQL92 (or according to my current understanding of same, anyway). Per pghackers discussion way back in March 2002: thread 'Do FROM items of different schemas conflict?'
1750 lines
46 KiB
C
1750 lines
46 KiB
C
/*-------------------------------------------------------------------------
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*
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* namespace.c
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* code to support accessing and searching namespaces
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*
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* This is separate from pg_namespace.c, which contains the routines that
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* directly manipulate the pg_namespace system catalog. This module
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* provides routines associated with defining a "namespace search path"
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* and implementing search-path-controlled searches.
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*
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*
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* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/catalog/namespace.c,v 1.29 2002/08/08 01:44:30 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/heapam.h"
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#include "access/xact.h"
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#include "catalog/catalog.h"
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#include "catalog/catname.h"
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#include "catalog/dependency.h"
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#include "catalog/heap.h"
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#include "catalog/namespace.h"
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#include "catalog/pg_conversion.h"
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#include "catalog/pg_inherits.h"
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#include "catalog/pg_namespace.h"
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#include "catalog/pg_opclass.h"
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#include "catalog/pg_operator.h"
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#include "catalog/pg_proc.h"
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#include "catalog/pg_shadow.h"
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#include "catalog/pg_type.h"
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#include "lib/stringinfo.h"
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#include "miscadmin.h"
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#include "nodes/makefuncs.h"
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#include "storage/backendid.h"
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#include "storage/ipc.h"
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#include "utils/acl.h"
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#include "utils/builtins.h"
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#include "utils/catcache.h"
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#include "utils/fmgroids.h"
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#include "utils/guc.h"
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#include "utils/inval.h"
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#include "utils/lsyscache.h"
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#include "utils/syscache.h"
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/*
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* The namespace search path is a possibly-empty list of namespace OIDs.
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* In addition to the explicit list, several implicitly-searched namespaces
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* may be included:
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*
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* 1. If a "special" namespace has been set by PushSpecialNamespace, it is
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* always searched first. (This is a hack for CREATE SCHEMA.)
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*
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* 2. If a TEMP table namespace has been initialized in this session, it
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* is always searched just after any special namespace.
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*
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* 3. The system catalog namespace is always searched. If the system
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* namespace is present in the explicit path then it will be searched in
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* the specified order; otherwise it will be searched after TEMP tables and
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* *before* the explicit list. (It might seem that the system namespace
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* should be implicitly last, but this behavior appears to be required by
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* SQL99. Also, this provides a way to search the system namespace first
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* without thereby making it the default creation target namespace.)
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*
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* The default creation target namespace is normally equal to the first
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* element of the explicit list, but is the "special" namespace when one
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* has been set. If the explicit list is empty and there is no special
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* namespace, there is no default target.
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*
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* In bootstrap mode, the search path is set equal to 'pg_catalog', so that
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* the system namespace is the only one searched or inserted into.
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* The initdb script is also careful to set search_path to 'pg_catalog' for
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* its post-bootstrap standalone backend runs. Otherwise the default search
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* path is determined by GUC. The factory default path contains the PUBLIC
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* namespace (if it exists), preceded by the user's personal namespace
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* (if one exists).
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*
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* If namespaceSearchPathValid is false, then namespaceSearchPath (and other
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* derived variables) need to be recomputed from namespace_search_path.
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* We mark it invalid upon an assignment to namespace_search_path or receipt
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* of a syscache invalidation event for pg_namespace. The recomputation
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* is done during the next lookup attempt.
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*
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* Any namespaces mentioned in namespace_search_path that are not readable
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* by the current user ID are simply left out of namespaceSearchPath; so
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* we have to be willing to recompute the path when current userid changes.
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* namespaceUser is the userid the path has been computed for.
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*/
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static List *namespaceSearchPath = NIL;
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static Oid namespaceUser = InvalidOid;
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/* default place to create stuff; if InvalidOid, no default */
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static Oid defaultCreationNamespace = InvalidOid;
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/* first explicit member of list; usually same as defaultCreationNamespace */
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static Oid firstExplicitNamespace = InvalidOid;
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/* The above four values are valid only if namespaceSearchPathValid */
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static bool namespaceSearchPathValid = true;
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/*
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* myTempNamespace is InvalidOid until and unless a TEMP namespace is set up
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* in a particular backend session (this happens when a CREATE TEMP TABLE
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* command is first executed). Thereafter it's the OID of the temp namespace.
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* firstTempTransaction flags whether we've committed creation of the TEMP
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* namespace or not.
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*/
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static Oid myTempNamespace = InvalidOid;
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static bool firstTempTransaction = false;
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/*
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* "Special" namespace for CREATE SCHEMA. If set, it's the first search
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* path element, and also the default creation namespace.
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*/
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static Oid mySpecialNamespace = InvalidOid;
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/*
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* This is the text equivalent of the search path --- it's the value
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* of the GUC variable 'search_path'.
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*/
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char *namespace_search_path = NULL;
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/* Local functions */
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static void recomputeNamespacePath(void);
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static void InitTempTableNamespace(void);
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static void RemoveTempRelations(Oid tempNamespaceId);
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static void RemoveTempRelationsCallback(void);
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static void NamespaceCallback(Datum arg, Oid relid);
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/*
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* RangeVarGetRelid
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* Given a RangeVar describing an existing relation,
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* select the proper namespace and look up the relation OID.
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*
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* If the relation is not found, return InvalidOid if failOK = true,
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* otherwise raise an error.
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*/
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Oid
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RangeVarGetRelid(const RangeVar *relation, bool failOK)
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{
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Oid namespaceId;
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Oid relId;
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/*
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* We check the catalog name and then ignore it.
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*/
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if (relation->catalogname)
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{
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if (strcmp(relation->catalogname, DatabaseName) != 0)
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elog(ERROR, "Cross-database references are not implemented");
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}
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if (relation->schemaname)
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{
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/* use exact schema given */
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namespaceId = LookupExplicitNamespace(relation->schemaname);
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relId = get_relname_relid(relation->relname, namespaceId);
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}
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else
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{
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/* search the namespace path */
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relId = RelnameGetRelid(relation->relname);
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}
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if (!OidIsValid(relId) && !failOK)
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{
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if (relation->schemaname)
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elog(ERROR, "Relation \"%s\".\"%s\" does not exist",
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relation->schemaname, relation->relname);
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else
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elog(ERROR, "Relation \"%s\" does not exist",
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relation->relname);
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}
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return relId;
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}
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/*
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* RangeVarGetCreationNamespace
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* Given a RangeVar describing a to-be-created relation,
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* choose which namespace to create it in.
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*
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* Note: calling this may result in a CommandCounterIncrement operation.
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* That will happen on the first request for a temp table in any particular
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* backend run; we will need to either create or clean out the temp schema.
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*/
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Oid
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RangeVarGetCreationNamespace(const RangeVar *newRelation)
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{
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Oid namespaceId;
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/*
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* We check the catalog name and then ignore it.
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*/
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if (newRelation->catalogname)
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{
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if (strcmp(newRelation->catalogname, DatabaseName) != 0)
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elog(ERROR, "Cross-database references are not implemented");
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}
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if (newRelation->istemp)
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{
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/* TEMP tables are created in our backend-local temp namespace */
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if (newRelation->schemaname)
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elog(ERROR, "TEMP tables may not specify a namespace");
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/* Initialize temp namespace if first time through */
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if (!OidIsValid(myTempNamespace))
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InitTempTableNamespace();
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return myTempNamespace;
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}
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if (newRelation->schemaname)
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{
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/* use exact schema given */
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namespaceId = GetSysCacheOid(NAMESPACENAME,
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CStringGetDatum(newRelation->schemaname),
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0, 0, 0);
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if (!OidIsValid(namespaceId))
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elog(ERROR, "Namespace \"%s\" does not exist",
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newRelation->schemaname);
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/* we do not check for USAGE rights here! */
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}
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else
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{
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/* use the default creation namespace */
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recomputeNamespacePath();
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namespaceId = defaultCreationNamespace;
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if (!OidIsValid(namespaceId))
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elog(ERROR, "No namespace has been selected to create in");
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}
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/* Note: callers will check for CREATE rights when appropriate */
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return namespaceId;
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}
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/*
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* RelnameGetRelid
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* Try to resolve an unqualified relation name.
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* Returns OID if relation found in search path, else InvalidOid.
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*/
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Oid
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RelnameGetRelid(const char *relname)
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{
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Oid relid;
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List *lptr;
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recomputeNamespacePath();
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foreach(lptr, namespaceSearchPath)
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{
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Oid namespaceId = (Oid) lfirsti(lptr);
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relid = get_relname_relid(relname, namespaceId);
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if (OidIsValid(relid))
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return relid;
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}
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/* Not found in path */
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return InvalidOid;
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}
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/*
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* RelationIsVisible
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* Determine whether a relation (identified by OID) is visible in the
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* current search path. Visible means "would be found by searching
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* for the unqualified relation name".
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*/
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bool
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RelationIsVisible(Oid relid)
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{
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HeapTuple reltup;
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Form_pg_class relform;
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Oid relnamespace;
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bool visible;
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reltup = SearchSysCache(RELOID,
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ObjectIdGetDatum(relid),
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0, 0, 0);
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if (!HeapTupleIsValid(reltup))
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elog(ERROR, "Cache lookup failed for relation %u", relid);
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relform = (Form_pg_class) GETSTRUCT(reltup);
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recomputeNamespacePath();
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/*
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* Quick check: if it ain't in the path at all, it ain't visible.
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* Items in the system namespace are surely in the path and so we
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* needn't even do intMember() for them.
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*/
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relnamespace = relform->relnamespace;
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if (relnamespace != PG_CATALOG_NAMESPACE &&
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!intMember(relnamespace, namespaceSearchPath))
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visible = false;
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else
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{
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/*
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* If it is in the path, it might still not be visible; it could be
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* hidden by another relation of the same name earlier in the path.
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* So we must do a slow check to see if this rel would be found by
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* RelnameGetRelid.
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*/
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char *relname = NameStr(relform->relname);
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visible = (RelnameGetRelid(relname) == relid);
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}
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ReleaseSysCache(reltup);
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return visible;
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}
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/*
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* TypenameGetTypid
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* Try to resolve an unqualified datatype name.
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* Returns OID if type found in search path, else InvalidOid.
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*
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* This is essentially the same as RelnameGetRelid.
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*/
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Oid
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TypenameGetTypid(const char *typname)
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{
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Oid typid;
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List *lptr;
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recomputeNamespacePath();
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foreach(lptr, namespaceSearchPath)
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{
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Oid namespaceId = (Oid) lfirsti(lptr);
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typid = GetSysCacheOid(TYPENAMENSP,
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PointerGetDatum(typname),
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ObjectIdGetDatum(namespaceId),
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0, 0);
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if (OidIsValid(typid))
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return typid;
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}
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/* Not found in path */
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return InvalidOid;
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}
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/*
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* TypeIsVisible
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* Determine whether a type (identified by OID) is visible in the
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* current search path. Visible means "would be found by searching
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* for the unqualified type name".
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*/
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bool
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TypeIsVisible(Oid typid)
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{
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HeapTuple typtup;
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Form_pg_type typform;
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Oid typnamespace;
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bool visible;
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typtup = SearchSysCache(TYPEOID,
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ObjectIdGetDatum(typid),
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0, 0, 0);
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if (!HeapTupleIsValid(typtup))
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elog(ERROR, "Cache lookup failed for type %u", typid);
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typform = (Form_pg_type) GETSTRUCT(typtup);
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recomputeNamespacePath();
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/*
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* Quick check: if it ain't in the path at all, it ain't visible.
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* Items in the system namespace are surely in the path and so we
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* needn't even do intMember() for them.
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*/
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typnamespace = typform->typnamespace;
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if (typnamespace != PG_CATALOG_NAMESPACE &&
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!intMember(typnamespace, namespaceSearchPath))
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visible = false;
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else
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{
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/*
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* If it is in the path, it might still not be visible; it could be
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* hidden by another type of the same name earlier in the path.
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* So we must do a slow check to see if this type would be found by
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* TypenameGetTypid.
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*/
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char *typname = NameStr(typform->typname);
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visible = (TypenameGetTypid(typname) == typid);
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}
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ReleaseSysCache(typtup);
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return visible;
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}
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/*
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* FuncnameGetCandidates
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* Given a possibly-qualified function name and argument count,
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* retrieve a list of the possible matches.
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*
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* If nargs is -1, we return all functions matching the given name,
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* regardless of argument count.
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*
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* We search a single namespace if the function name is qualified, else
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* all namespaces in the search path. The return list will never contain
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* multiple entries with identical argument lists --- in the multiple-
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* namespace case, we arrange for entries in earlier namespaces to mask
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* identical entries in later namespaces.
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*/
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FuncCandidateList
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FuncnameGetCandidates(List *names, int nargs)
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{
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FuncCandidateList resultList = NULL;
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char *schemaname;
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char *funcname;
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Oid namespaceId;
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CatCList *catlist;
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int i;
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/* deconstruct the name list */
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DeconstructQualifiedName(names, &schemaname, &funcname);
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if (schemaname)
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{
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/* use exact schema given */
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namespaceId = LookupExplicitNamespace(schemaname);
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}
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else
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{
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/* flag to indicate we need namespace search */
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namespaceId = InvalidOid;
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recomputeNamespacePath();
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}
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/* Search syscache by name and (optionally) nargs only */
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if (nargs >= 0)
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catlist = SearchSysCacheList(PROCNAMENSP, 2,
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CStringGetDatum(funcname),
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Int16GetDatum(nargs),
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0, 0);
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else
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catlist = SearchSysCacheList(PROCNAMENSP, 1,
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CStringGetDatum(funcname),
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0, 0, 0);
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for (i = 0; i < catlist->n_members; i++)
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{
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HeapTuple proctup = &catlist->members[i]->tuple;
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Form_pg_proc procform = (Form_pg_proc) GETSTRUCT(proctup);
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int pathpos = 0;
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FuncCandidateList newResult;
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nargs = procform->pronargs;
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if (OidIsValid(namespaceId))
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{
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/* Consider only procs in specified namespace */
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if (procform->pronamespace != namespaceId)
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continue;
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/* No need to check args, they must all be different */
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}
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else
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{
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/* Consider only procs that are in the search path */
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List *nsp;
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foreach(nsp, namespaceSearchPath)
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{
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if (procform->pronamespace == (Oid) lfirsti(nsp))
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break;
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pathpos++;
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}
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if (nsp == NIL)
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continue; /* proc is not in search path */
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/*
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* Okay, it's in the search path, but does it have the same
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* arguments as something we already accepted? If so, keep
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* only the one that appears earlier in the search path.
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*
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* If we have an ordered list from SearchSysCacheList (the
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* normal case), then any conflicting proc must immediately
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* adjoin this one in the list, so we only need to look at
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* the newest result item. If we have an unordered list,
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* we have to scan the whole result list.
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*/
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if (resultList)
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{
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FuncCandidateList prevResult;
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|
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if (catlist->ordered)
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{
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if (nargs == resultList->nargs &&
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memcmp(procform->proargtypes, resultList->args,
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nargs * sizeof(Oid)) == 0)
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prevResult = resultList;
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else
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prevResult = NULL;
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}
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else
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{
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for (prevResult = resultList;
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prevResult;
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prevResult = prevResult->next)
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{
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if (nargs == prevResult->nargs &&
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memcmp(procform->proargtypes, prevResult->args,
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nargs * sizeof(Oid)) == 0)
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break;
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}
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}
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if (prevResult)
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{
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/* We have a match with a previous result */
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Assert(pathpos != prevResult->pathpos);
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if (pathpos > prevResult->pathpos)
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continue; /* keep previous result */
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/* replace previous result */
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prevResult->pathpos = pathpos;
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prevResult->oid = HeapTupleGetOid(proctup);
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continue; /* args are same, of course */
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}
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}
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}
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|
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/*
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* Okay to add it to result list
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*/
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newResult = (FuncCandidateList)
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palloc(sizeof(struct _FuncCandidateList) - sizeof(Oid)
|
|
+ nargs * sizeof(Oid));
|
|
newResult->pathpos = pathpos;
|
|
newResult->oid = HeapTupleGetOid(proctup);
|
|
newResult->nargs = nargs;
|
|
memcpy(newResult->args, procform->proargtypes, nargs * sizeof(Oid));
|
|
|
|
newResult->next = resultList;
|
|
resultList = newResult;
|
|
}
|
|
|
|
ReleaseSysCacheList(catlist);
|
|
|
|
return resultList;
|
|
}
|
|
|
|
/*
|
|
* FunctionIsVisible
|
|
* Determine whether a function (identified by OID) is visible in the
|
|
* current search path. Visible means "would be found by searching
|
|
* for the unqualified function name with exact argument matches".
|
|
*/
|
|
bool
|
|
FunctionIsVisible(Oid funcid)
|
|
{
|
|
HeapTuple proctup;
|
|
Form_pg_proc procform;
|
|
Oid pronamespace;
|
|
bool visible;
|
|
|
|
proctup = SearchSysCache(PROCOID,
|
|
ObjectIdGetDatum(funcid),
|
|
0, 0, 0);
|
|
if (!HeapTupleIsValid(proctup))
|
|
elog(ERROR, "Cache lookup failed for procedure %u", funcid);
|
|
procform = (Form_pg_proc) GETSTRUCT(proctup);
|
|
|
|
recomputeNamespacePath();
|
|
|
|
/*
|
|
* Quick check: if it ain't in the path at all, it ain't visible.
|
|
* Items in the system namespace are surely in the path and so we
|
|
* needn't even do intMember() for them.
|
|
*/
|
|
pronamespace = procform->pronamespace;
|
|
if (pronamespace != PG_CATALOG_NAMESPACE &&
|
|
!intMember(pronamespace, namespaceSearchPath))
|
|
visible = false;
|
|
else
|
|
{
|
|
/*
|
|
* If it is in the path, it might still not be visible; it could be
|
|
* hidden by another proc of the same name and arguments earlier
|
|
* in the path. So we must do a slow check to see if this is the
|
|
* same proc that would be found by FuncnameGetCandidates.
|
|
*/
|
|
char *proname = NameStr(procform->proname);
|
|
int nargs = procform->pronargs;
|
|
FuncCandidateList clist;
|
|
|
|
visible = false;
|
|
|
|
clist = FuncnameGetCandidates(makeList1(makeString(proname)), nargs);
|
|
|
|
for (; clist; clist = clist->next)
|
|
{
|
|
if (memcmp(clist->args, procform->proargtypes,
|
|
nargs * sizeof(Oid)) == 0)
|
|
{
|
|
/* Found the expected entry; is it the right proc? */
|
|
visible = (clist->oid == funcid);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
ReleaseSysCache(proctup);
|
|
|
|
return visible;
|
|
}
|
|
|
|
|
|
/*
|
|
* OpernameGetCandidates
|
|
* Given a possibly-qualified operator name and operator kind,
|
|
* retrieve a list of the possible matches.
|
|
*
|
|
* If oprkind is '\0', we return all operators matching the given name,
|
|
* regardless of arguments.
|
|
*
|
|
* We search a single namespace if the operator name is qualified, else
|
|
* all namespaces in the search path. The return list will never contain
|
|
* multiple entries with identical argument lists --- in the multiple-
|
|
* namespace case, we arrange for entries in earlier namespaces to mask
|
|
* identical entries in later namespaces.
|
|
*
|
|
* The returned items always have two args[] entries --- one or the other
|
|
* will be InvalidOid for a prefix or postfix oprkind. nargs is 2, too.
|
|
*/
|
|
FuncCandidateList
|
|
OpernameGetCandidates(List *names, char oprkind)
|
|
{
|
|
FuncCandidateList resultList = NULL;
|
|
char *schemaname;
|
|
char *opername;
|
|
Oid namespaceId;
|
|
CatCList *catlist;
|
|
int i;
|
|
|
|
/* deconstruct the name list */
|
|
DeconstructQualifiedName(names, &schemaname, &opername);
|
|
|
|
if (schemaname)
|
|
{
|
|
/* use exact schema given */
|
|
namespaceId = LookupExplicitNamespace(schemaname);
|
|
}
|
|
else
|
|
{
|
|
/* flag to indicate we need namespace search */
|
|
namespaceId = InvalidOid;
|
|
recomputeNamespacePath();
|
|
}
|
|
|
|
/* Search syscache by name only */
|
|
catlist = SearchSysCacheList(OPERNAMENSP, 1,
|
|
CStringGetDatum(opername),
|
|
0, 0, 0);
|
|
|
|
for (i = 0; i < catlist->n_members; i++)
|
|
{
|
|
HeapTuple opertup = &catlist->members[i]->tuple;
|
|
Form_pg_operator operform = (Form_pg_operator) GETSTRUCT(opertup);
|
|
int pathpos = 0;
|
|
FuncCandidateList newResult;
|
|
|
|
/* Ignore operators of wrong kind, if specific kind requested */
|
|
if (oprkind && operform->oprkind != oprkind)
|
|
continue;
|
|
|
|
if (OidIsValid(namespaceId))
|
|
{
|
|
/* Consider only opers in specified namespace */
|
|
if (operform->oprnamespace != namespaceId)
|
|
continue;
|
|
/* No need to check args, they must all be different */
|
|
}
|
|
else
|
|
{
|
|
/* Consider only opers that are in the search path */
|
|
List *nsp;
|
|
|
|
foreach(nsp, namespaceSearchPath)
|
|
{
|
|
if (operform->oprnamespace == (Oid) lfirsti(nsp))
|
|
break;
|
|
pathpos++;
|
|
}
|
|
if (nsp == NIL)
|
|
continue; /* oper is not in search path */
|
|
|
|
/*
|
|
* Okay, it's in the search path, but does it have the same
|
|
* arguments as something we already accepted? If so, keep
|
|
* only the one that appears earlier in the search path.
|
|
*
|
|
* If we have an ordered list from SearchSysCacheList (the
|
|
* normal case), then any conflicting oper must immediately
|
|
* adjoin this one in the list, so we only need to look at
|
|
* the newest result item. If we have an unordered list,
|
|
* we have to scan the whole result list.
|
|
*/
|
|
if (resultList)
|
|
{
|
|
FuncCandidateList prevResult;
|
|
|
|
if (catlist->ordered)
|
|
{
|
|
if (operform->oprleft == resultList->args[0] &&
|
|
operform->oprright == resultList->args[1])
|
|
prevResult = resultList;
|
|
else
|
|
prevResult = NULL;
|
|
}
|
|
else
|
|
{
|
|
for (prevResult = resultList;
|
|
prevResult;
|
|
prevResult = prevResult->next)
|
|
{
|
|
if (operform->oprleft == prevResult->args[0] &&
|
|
operform->oprright == prevResult->args[1])
|
|
break;
|
|
}
|
|
}
|
|
if (prevResult)
|
|
{
|
|
/* We have a match with a previous result */
|
|
Assert(pathpos != prevResult->pathpos);
|
|
if (pathpos > prevResult->pathpos)
|
|
continue; /* keep previous result */
|
|
/* replace previous result */
|
|
prevResult->pathpos = pathpos;
|
|
prevResult->oid = HeapTupleGetOid(opertup);
|
|
continue; /* args are same, of course */
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Okay to add it to result list
|
|
*/
|
|
newResult = (FuncCandidateList)
|
|
palloc(sizeof(struct _FuncCandidateList) + sizeof(Oid));
|
|
newResult->pathpos = pathpos;
|
|
newResult->oid = HeapTupleGetOid(opertup);
|
|
newResult->nargs = 2;
|
|
newResult->args[0] = operform->oprleft;
|
|
newResult->args[1] = operform->oprright;
|
|
newResult->next = resultList;
|
|
resultList = newResult;
|
|
}
|
|
|
|
ReleaseSysCacheList(catlist);
|
|
|
|
return resultList;
|
|
}
|
|
|
|
/*
|
|
* OperatorIsVisible
|
|
* Determine whether an operator (identified by OID) is visible in the
|
|
* current search path. Visible means "would be found by searching
|
|
* for the unqualified operator name with exact argument matches".
|
|
*/
|
|
bool
|
|
OperatorIsVisible(Oid oprid)
|
|
{
|
|
HeapTuple oprtup;
|
|
Form_pg_operator oprform;
|
|
Oid oprnamespace;
|
|
bool visible;
|
|
|
|
oprtup = SearchSysCache(OPEROID,
|
|
ObjectIdGetDatum(oprid),
|
|
0, 0, 0);
|
|
if (!HeapTupleIsValid(oprtup))
|
|
elog(ERROR, "Cache lookup failed for operator %u", oprid);
|
|
oprform = (Form_pg_operator) GETSTRUCT(oprtup);
|
|
|
|
recomputeNamespacePath();
|
|
|
|
/*
|
|
* Quick check: if it ain't in the path at all, it ain't visible.
|
|
* Items in the system namespace are surely in the path and so we
|
|
* needn't even do intMember() for them.
|
|
*/
|
|
oprnamespace = oprform->oprnamespace;
|
|
if (oprnamespace != PG_CATALOG_NAMESPACE &&
|
|
!intMember(oprnamespace, namespaceSearchPath))
|
|
visible = false;
|
|
else
|
|
{
|
|
/*
|
|
* If it is in the path, it might still not be visible; it could be
|
|
* hidden by another operator of the same name and arguments earlier
|
|
* in the path. So we must do a slow check to see if this is the
|
|
* same operator that would be found by OpernameGetCandidates.
|
|
*/
|
|
char *oprname = NameStr(oprform->oprname);
|
|
FuncCandidateList clist;
|
|
|
|
visible = false;
|
|
|
|
clist = OpernameGetCandidates(makeList1(makeString(oprname)),
|
|
oprform->oprkind);
|
|
|
|
for (; clist; clist = clist->next)
|
|
{
|
|
if (clist->args[0] == oprform->oprleft &&
|
|
clist->args[1] == oprform->oprright)
|
|
{
|
|
/* Found the expected entry; is it the right op? */
|
|
visible = (clist->oid == oprid);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
ReleaseSysCache(oprtup);
|
|
|
|
return visible;
|
|
}
|
|
|
|
|
|
/*
|
|
* OpclassGetCandidates
|
|
* Given an index access method OID, retrieve a list of all the
|
|
* opclasses for that AM that are visible in the search path.
|
|
*
|
|
* NOTE: the opcname_tmp field in the returned structs should not be used
|
|
* by callers, because it points at syscache entries that we release at
|
|
* the end of this routine. If any callers needed the name information,
|
|
* we could pstrdup() the names ... but at present it'd be wasteful.
|
|
*/
|
|
OpclassCandidateList
|
|
OpclassGetCandidates(Oid amid)
|
|
{
|
|
OpclassCandidateList resultList = NULL;
|
|
CatCList *catlist;
|
|
int i;
|
|
|
|
/* Search syscache by AM OID only */
|
|
catlist = SearchSysCacheList(CLAAMNAMENSP, 1,
|
|
ObjectIdGetDatum(amid),
|
|
0, 0, 0);
|
|
|
|
recomputeNamespacePath();
|
|
|
|
for (i = 0; i < catlist->n_members; i++)
|
|
{
|
|
HeapTuple opctup = &catlist->members[i]->tuple;
|
|
Form_pg_opclass opcform = (Form_pg_opclass) GETSTRUCT(opctup);
|
|
int pathpos = 0;
|
|
OpclassCandidateList newResult;
|
|
List *nsp;
|
|
|
|
/* Consider only opclasses that are in the search path */
|
|
foreach(nsp, namespaceSearchPath)
|
|
{
|
|
if (opcform->opcnamespace == (Oid) lfirsti(nsp))
|
|
break;
|
|
pathpos++;
|
|
}
|
|
if (nsp == NIL)
|
|
continue; /* opclass is not in search path */
|
|
|
|
/*
|
|
* Okay, it's in the search path, but does it have the same name
|
|
* as something we already accepted? If so, keep
|
|
* only the one that appears earlier in the search path.
|
|
*
|
|
* If we have an ordered list from SearchSysCacheList (the
|
|
* normal case), then any conflicting opclass must immediately
|
|
* adjoin this one in the list, so we only need to look at
|
|
* the newest result item. If we have an unordered list,
|
|
* we have to scan the whole result list.
|
|
*/
|
|
if (resultList)
|
|
{
|
|
OpclassCandidateList prevResult;
|
|
|
|
if (catlist->ordered)
|
|
{
|
|
if (strcmp(NameStr(opcform->opcname),
|
|
resultList->opcname_tmp) == 0)
|
|
prevResult = resultList;
|
|
else
|
|
prevResult = NULL;
|
|
}
|
|
else
|
|
{
|
|
for (prevResult = resultList;
|
|
prevResult;
|
|
prevResult = prevResult->next)
|
|
{
|
|
if (strcmp(NameStr(opcform->opcname),
|
|
prevResult->opcname_tmp) == 0)
|
|
break;
|
|
}
|
|
}
|
|
if (prevResult)
|
|
{
|
|
/* We have a match with a previous result */
|
|
Assert(pathpos != prevResult->pathpos);
|
|
if (pathpos > prevResult->pathpos)
|
|
continue; /* keep previous result */
|
|
/* replace previous result */
|
|
prevResult->opcname_tmp = NameStr(opcform->opcname);
|
|
prevResult->pathpos = pathpos;
|
|
prevResult->oid = HeapTupleGetOid(opctup);
|
|
prevResult->opcintype = opcform->opcintype;
|
|
prevResult->opcdefault = opcform->opcdefault;
|
|
prevResult->opckeytype = opcform->opckeytype;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Okay to add it to result list
|
|
*/
|
|
newResult = (OpclassCandidateList)
|
|
palloc(sizeof(struct _OpclassCandidateList));
|
|
newResult->opcname_tmp = NameStr(opcform->opcname);
|
|
newResult->pathpos = pathpos;
|
|
newResult->oid = HeapTupleGetOid(opctup);
|
|
newResult->opcintype = opcform->opcintype;
|
|
newResult->opcdefault = opcform->opcdefault;
|
|
newResult->opckeytype = opcform->opckeytype;
|
|
newResult->next = resultList;
|
|
resultList = newResult;
|
|
}
|
|
|
|
ReleaseSysCacheList(catlist);
|
|
|
|
return resultList;
|
|
}
|
|
|
|
/*
|
|
* OpclassnameGetOpcid
|
|
* Try to resolve an unqualified index opclass name.
|
|
* Returns OID if opclass found in search path, else InvalidOid.
|
|
*
|
|
* This is essentially the same as TypenameGetTypid, but we have to have
|
|
* an extra argument for the index AM OID.
|
|
*/
|
|
Oid
|
|
OpclassnameGetOpcid(Oid amid, const char *opcname)
|
|
{
|
|
Oid opcid;
|
|
List *lptr;
|
|
|
|
recomputeNamespacePath();
|
|
|
|
foreach(lptr, namespaceSearchPath)
|
|
{
|
|
Oid namespaceId = (Oid) lfirsti(lptr);
|
|
|
|
opcid = GetSysCacheOid(CLAAMNAMENSP,
|
|
ObjectIdGetDatum(amid),
|
|
PointerGetDatum(opcname),
|
|
ObjectIdGetDatum(namespaceId),
|
|
0);
|
|
if (OidIsValid(opcid))
|
|
return opcid;
|
|
}
|
|
|
|
/* Not found in path */
|
|
return InvalidOid;
|
|
}
|
|
|
|
/*
|
|
* OpclassIsVisible
|
|
* Determine whether an opclass (identified by OID) is visible in the
|
|
* current search path. Visible means "would be found by searching
|
|
* for the unqualified opclass name".
|
|
*/
|
|
bool
|
|
OpclassIsVisible(Oid opcid)
|
|
{
|
|
HeapTuple opctup;
|
|
Form_pg_opclass opcform;
|
|
Oid opcnamespace;
|
|
bool visible;
|
|
|
|
opctup = SearchSysCache(CLAOID,
|
|
ObjectIdGetDatum(opcid),
|
|
0, 0, 0);
|
|
if (!HeapTupleIsValid(opctup))
|
|
elog(ERROR, "Cache lookup failed for opclass %u", opcid);
|
|
opcform = (Form_pg_opclass) GETSTRUCT(opctup);
|
|
|
|
recomputeNamespacePath();
|
|
|
|
/*
|
|
* Quick check: if it ain't in the path at all, it ain't visible.
|
|
* Items in the system namespace are surely in the path and so we
|
|
* needn't even do intMember() for them.
|
|
*/
|
|
opcnamespace = opcform->opcnamespace;
|
|
if (opcnamespace != PG_CATALOG_NAMESPACE &&
|
|
!intMember(opcnamespace, namespaceSearchPath))
|
|
visible = false;
|
|
else
|
|
{
|
|
/*
|
|
* If it is in the path, it might still not be visible; it could be
|
|
* hidden by another opclass of the same name earlier in the path.
|
|
* So we must do a slow check to see if this opclass would be found by
|
|
* OpclassnameGetOpcid.
|
|
*/
|
|
char *opcname = NameStr(opcform->opcname);
|
|
|
|
visible = (OpclassnameGetOpcid(opcform->opcamid, opcname) == opcid);
|
|
}
|
|
|
|
ReleaseSysCache(opctup);
|
|
|
|
return visible;
|
|
}
|
|
|
|
/*
|
|
* DeconstructQualifiedName
|
|
* Given a possibly-qualified name expressed as a list of String nodes,
|
|
* extract the schema name and object name.
|
|
*
|
|
* *nspname_p is set to NULL if there is no explicit schema name.
|
|
*/
|
|
void
|
|
DeconstructQualifiedName(List *names,
|
|
char **nspname_p,
|
|
char **objname_p)
|
|
{
|
|
char *catalogname;
|
|
char *schemaname = NULL;
|
|
char *objname = NULL;
|
|
|
|
switch (length(names))
|
|
{
|
|
case 1:
|
|
objname = strVal(lfirst(names));
|
|
break;
|
|
case 2:
|
|
schemaname = strVal(lfirst(names));
|
|
objname = strVal(lsecond(names));
|
|
break;
|
|
case 3:
|
|
catalogname = strVal(lfirst(names));
|
|
schemaname = strVal(lsecond(names));
|
|
objname = strVal(lfirst(lnext(lnext(names))));
|
|
/*
|
|
* We check the catalog name and then ignore it.
|
|
*/
|
|
if (strcmp(catalogname, DatabaseName) != 0)
|
|
elog(ERROR, "Cross-database references are not implemented");
|
|
break;
|
|
default:
|
|
elog(ERROR, "Improper qualified name (too many dotted names): %s",
|
|
NameListToString(names));
|
|
break;
|
|
}
|
|
|
|
*nspname_p = schemaname;
|
|
*objname_p = objname;
|
|
}
|
|
|
|
/*
|
|
* LookupExplicitNamespace
|
|
* Process an explicitly-specified schema name: look up the schema
|
|
* and verify we have USAGE (lookup) rights in it.
|
|
*
|
|
* Returns the namespace OID. Raises elog if any problem.
|
|
*/
|
|
Oid
|
|
LookupExplicitNamespace(const char *nspname)
|
|
{
|
|
Oid namespaceId;
|
|
AclResult aclresult;
|
|
|
|
namespaceId = GetSysCacheOid(NAMESPACENAME,
|
|
CStringGetDatum(nspname),
|
|
0, 0, 0);
|
|
if (!OidIsValid(namespaceId))
|
|
elog(ERROR, "Namespace \"%s\" does not exist", nspname);
|
|
|
|
aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_USAGE);
|
|
if (aclresult != ACLCHECK_OK)
|
|
aclcheck_error(aclresult, nspname);
|
|
|
|
return namespaceId;
|
|
}
|
|
|
|
/*
|
|
* QualifiedNameGetCreationNamespace
|
|
* Given a possibly-qualified name for an object (in List-of-Values
|
|
* format), determine what namespace the object should be created in.
|
|
* Also extract and return the object name (last component of list).
|
|
*
|
|
* This is *not* used for tables. Hence, the TEMP table namespace is
|
|
* never selected as the creation target.
|
|
*/
|
|
Oid
|
|
QualifiedNameGetCreationNamespace(List *names, char **objname_p)
|
|
{
|
|
char *schemaname;
|
|
char *objname;
|
|
Oid namespaceId;
|
|
|
|
/* deconstruct the name list */
|
|
DeconstructQualifiedName(names, &schemaname, &objname);
|
|
|
|
if (schemaname)
|
|
{
|
|
/* use exact schema given */
|
|
namespaceId = GetSysCacheOid(NAMESPACENAME,
|
|
CStringGetDatum(schemaname),
|
|
0, 0, 0);
|
|
if (!OidIsValid(namespaceId))
|
|
elog(ERROR, "Namespace \"%s\" does not exist",
|
|
schemaname);
|
|
/* we do not check for USAGE rights here! */
|
|
}
|
|
else
|
|
{
|
|
/* use the default creation namespace */
|
|
recomputeNamespacePath();
|
|
namespaceId = defaultCreationNamespace;
|
|
if (!OidIsValid(namespaceId))
|
|
elog(ERROR, "No namespace has been selected to create in");
|
|
}
|
|
|
|
/* Note: callers will check for CREATE rights when appropriate */
|
|
|
|
*objname_p = objname;
|
|
return namespaceId;
|
|
}
|
|
|
|
/*
|
|
* makeRangeVarFromNameList
|
|
* Utility routine to convert a qualified-name list into RangeVar form.
|
|
*/
|
|
RangeVar *
|
|
makeRangeVarFromNameList(List *names)
|
|
{
|
|
RangeVar *rel = makeRangeVar(NULL, NULL);
|
|
|
|
switch (length(names))
|
|
{
|
|
case 1:
|
|
rel->relname = strVal(lfirst(names));
|
|
break;
|
|
case 2:
|
|
rel->schemaname = strVal(lfirst(names));
|
|
rel->relname = strVal(lsecond(names));
|
|
break;
|
|
case 3:
|
|
rel->catalogname = strVal(lfirst(names));
|
|
rel->schemaname = strVal(lsecond(names));
|
|
rel->relname = strVal(lfirst(lnext(lnext(names))));
|
|
break;
|
|
default:
|
|
elog(ERROR, "Improper relation name (too many dotted names)");
|
|
break;
|
|
}
|
|
|
|
return rel;
|
|
}
|
|
|
|
/*
|
|
* NameListToString
|
|
* Utility routine to convert a qualified-name list into a string.
|
|
* Used primarily to form error messages.
|
|
*/
|
|
char *
|
|
NameListToString(List *names)
|
|
{
|
|
StringInfoData string;
|
|
List *l;
|
|
|
|
initStringInfo(&string);
|
|
|
|
foreach(l, names)
|
|
{
|
|
if (l != names)
|
|
appendStringInfoChar(&string, '.');
|
|
appendStringInfo(&string, "%s", strVal(lfirst(l)));
|
|
}
|
|
|
|
return string.data;
|
|
}
|
|
|
|
/*
|
|
* isTempNamespace - is the given namespace my temporary-table namespace?
|
|
*/
|
|
bool
|
|
isTempNamespace(Oid namespaceId)
|
|
{
|
|
if (OidIsValid(myTempNamespace) && myTempNamespace == namespaceId)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* PushSpecialNamespace - push a "special" namespace onto the front of the
|
|
* search path.
|
|
*
|
|
* This is a slightly messy hack intended only for support of CREATE SCHEMA.
|
|
* Although the API is defined to allow a stack of pushed namespaces, we
|
|
* presently only support one at a time.
|
|
*
|
|
* The pushed namespace will be removed from the search path at end of
|
|
* transaction, whether commit or abort.
|
|
*/
|
|
void
|
|
PushSpecialNamespace(Oid namespaceId)
|
|
{
|
|
Assert(!OidIsValid(mySpecialNamespace));
|
|
mySpecialNamespace = namespaceId;
|
|
namespaceSearchPathValid = false;
|
|
}
|
|
|
|
/*
|
|
* PopSpecialNamespace - remove previously pushed special namespace.
|
|
*/
|
|
void
|
|
PopSpecialNamespace(Oid namespaceId)
|
|
{
|
|
Assert(mySpecialNamespace == namespaceId);
|
|
mySpecialNamespace = InvalidOid;
|
|
namespaceSearchPathValid = false;
|
|
}
|
|
|
|
/*
|
|
* FindConversionByName - find a conversion by possibly qualified name
|
|
*/
|
|
Oid FindConversionByName(List *name)
|
|
{
|
|
char *conversion_name;
|
|
Oid namespaceId;
|
|
Oid conoid;
|
|
List *lptr;
|
|
|
|
/* Convert list of names to a name and namespace */
|
|
namespaceId = QualifiedNameGetCreationNamespace(name, &conversion_name);
|
|
|
|
if (length(name) > 1)
|
|
{
|
|
/* Check we have usage rights in target namespace */
|
|
if (pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_USAGE) != ACLCHECK_OK)
|
|
return InvalidOid;
|
|
|
|
return FindConversion(conversion_name, namespaceId);
|
|
}
|
|
|
|
recomputeNamespacePath();
|
|
|
|
foreach(lptr, namespaceSearchPath)
|
|
{
|
|
Oid namespaceId = (Oid) lfirsti(lptr);
|
|
|
|
conoid = FindConversion(conversion_name, namespaceId);
|
|
if (OidIsValid(conoid))
|
|
return conoid;
|
|
}
|
|
|
|
/* Not found in path */
|
|
return InvalidOid;
|
|
}
|
|
|
|
/*
|
|
* FindDefaultConversionProc - find default encoding cnnversion proc
|
|
*/
|
|
Oid FindDefaultConversionProc(int4 for_encoding, int4 to_encoding)
|
|
{
|
|
Oid proc;
|
|
List *lptr;
|
|
|
|
recomputeNamespacePath();
|
|
|
|
foreach(lptr, namespaceSearchPath)
|
|
{
|
|
Oid namespaceId = (Oid) lfirsti(lptr);
|
|
|
|
proc = FindDefaultConversion(namespaceId, for_encoding, to_encoding);
|
|
if (OidIsValid(proc))
|
|
return proc;
|
|
}
|
|
|
|
/* Not found in path */
|
|
return InvalidOid;
|
|
}
|
|
|
|
/*
|
|
* recomputeNamespacePath - recompute path derived variables if needed.
|
|
*/
|
|
static void
|
|
recomputeNamespacePath(void)
|
|
{
|
|
Oid userId = GetUserId();
|
|
char *rawname;
|
|
List *namelist;
|
|
List *oidlist;
|
|
List *newpath;
|
|
List *l;
|
|
Oid firstNS;
|
|
MemoryContext oldcxt;
|
|
|
|
/*
|
|
* Do nothing if path is already valid.
|
|
*/
|
|
if (namespaceSearchPathValid && namespaceUser == userId)
|
|
return;
|
|
|
|
/* Need a modifiable copy of namespace_search_path string */
|
|
rawname = pstrdup(namespace_search_path);
|
|
|
|
/* Parse string into list of identifiers */
|
|
if (!SplitIdentifierString(rawname, ',', &namelist))
|
|
{
|
|
/* syntax error in name list */
|
|
/* this should not happen if GUC checked check_search_path */
|
|
elog(ERROR, "recomputeNamespacePath: invalid list syntax");
|
|
}
|
|
|
|
/*
|
|
* Convert the list of names to a list of OIDs. If any names are not
|
|
* recognizable or we don't have read access, just leave them out of
|
|
* the list. (We can't raise an error, since the search_path setting
|
|
* has already been accepted.) Don't make duplicate entries, either.
|
|
*/
|
|
oidlist = NIL;
|
|
foreach(l, namelist)
|
|
{
|
|
char *curname = (char *) lfirst(l);
|
|
Oid namespaceId;
|
|
|
|
if (strcmp(curname, "$user") == 0)
|
|
{
|
|
/* $user --- substitute namespace matching user name, if any */
|
|
HeapTuple tuple;
|
|
|
|
tuple = SearchSysCache(SHADOWSYSID,
|
|
ObjectIdGetDatum(userId),
|
|
0, 0, 0);
|
|
if (HeapTupleIsValid(tuple))
|
|
{
|
|
char *uname;
|
|
|
|
uname = NameStr(((Form_pg_shadow) GETSTRUCT(tuple))->usename);
|
|
namespaceId = GetSysCacheOid(NAMESPACENAME,
|
|
CStringGetDatum(uname),
|
|
0, 0, 0);
|
|
ReleaseSysCache(tuple);
|
|
if (OidIsValid(namespaceId) &&
|
|
!intMember(namespaceId, oidlist) &&
|
|
pg_namespace_aclcheck(namespaceId, userId,
|
|
ACL_USAGE) == ACLCHECK_OK)
|
|
oidlist = lappendi(oidlist, namespaceId);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* normal namespace reference */
|
|
namespaceId = GetSysCacheOid(NAMESPACENAME,
|
|
CStringGetDatum(curname),
|
|
0, 0, 0);
|
|
if (OidIsValid(namespaceId) &&
|
|
!intMember(namespaceId, oidlist) &&
|
|
pg_namespace_aclcheck(namespaceId, userId,
|
|
ACL_USAGE) == ACLCHECK_OK)
|
|
oidlist = lappendi(oidlist, namespaceId);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remember the first member of the explicit list.
|
|
*/
|
|
if (oidlist == NIL)
|
|
firstNS = InvalidOid;
|
|
else
|
|
firstNS = (Oid) lfirsti(oidlist);
|
|
|
|
/*
|
|
* Add any implicitly-searched namespaces to the list. Note these
|
|
* go on the front, not the back; also notice that we do not check
|
|
* USAGE permissions for these.
|
|
*/
|
|
if (!intMember(PG_CATALOG_NAMESPACE, oidlist))
|
|
oidlist = lconsi(PG_CATALOG_NAMESPACE, oidlist);
|
|
|
|
if (OidIsValid(myTempNamespace) &&
|
|
!intMember(myTempNamespace, oidlist))
|
|
oidlist = lconsi(myTempNamespace, oidlist);
|
|
|
|
if (OidIsValid(mySpecialNamespace) &&
|
|
!intMember(mySpecialNamespace, oidlist))
|
|
oidlist = lconsi(mySpecialNamespace, oidlist);
|
|
|
|
/*
|
|
* Now that we've successfully built the new list of namespace OIDs,
|
|
* save it in permanent storage.
|
|
*/
|
|
oldcxt = MemoryContextSwitchTo(TopMemoryContext);
|
|
newpath = listCopy(oidlist);
|
|
MemoryContextSwitchTo(oldcxt);
|
|
|
|
/* Now safe to assign to state variable. */
|
|
freeList(namespaceSearchPath);
|
|
namespaceSearchPath = newpath;
|
|
|
|
/*
|
|
* Update info derived from search path.
|
|
*/
|
|
firstExplicitNamespace = firstNS;
|
|
if (OidIsValid(mySpecialNamespace))
|
|
defaultCreationNamespace = mySpecialNamespace;
|
|
else
|
|
defaultCreationNamespace = firstNS;
|
|
|
|
/* Mark the path valid. */
|
|
namespaceSearchPathValid = true;
|
|
namespaceUser = userId;
|
|
|
|
/* Clean up. */
|
|
pfree(rawname);
|
|
freeList(namelist);
|
|
freeList(oidlist);
|
|
}
|
|
|
|
/*
|
|
* InitTempTableNamespace
|
|
* Initialize temp table namespace on first use in a particular backend
|
|
*/
|
|
static void
|
|
InitTempTableNamespace(void)
|
|
{
|
|
char namespaceName[NAMEDATALEN];
|
|
Oid namespaceId;
|
|
|
|
/*
|
|
* First, do permission check to see if we are authorized to make
|
|
* temp tables. We use a nonstandard error message here since
|
|
* "databasename: permission denied" might be a tad cryptic.
|
|
*
|
|
* Note we apply the check to the session user, not the currently
|
|
* active userid, since we are not going to change our minds about
|
|
* temp table availability during the session.
|
|
*/
|
|
if (pg_database_aclcheck(MyDatabaseId, GetSessionUserId(),
|
|
ACL_CREATE_TEMP) != ACLCHECK_OK)
|
|
elog(ERROR, "%s: not authorized to create temp tables",
|
|
DatabaseName);
|
|
|
|
snprintf(namespaceName, NAMEDATALEN, "pg_temp_%d", MyBackendId);
|
|
|
|
namespaceId = GetSysCacheOid(NAMESPACENAME,
|
|
CStringGetDatum(namespaceName),
|
|
0, 0, 0);
|
|
if (!OidIsValid(namespaceId))
|
|
{
|
|
/*
|
|
* First use of this temp namespace in this database; create it.
|
|
* The temp namespaces are always owned by the superuser. We
|
|
* leave their permissions at default --- i.e., no access except to
|
|
* superuser --- to ensure that unprivileged users can't peek
|
|
* at other backends' temp tables. This works because the places
|
|
* that access the temp namespace for my own backend skip permissions
|
|
* checks on it.
|
|
*/
|
|
namespaceId = NamespaceCreate(namespaceName, BOOTSTRAP_USESYSID);
|
|
/* Advance command counter to make namespace visible */
|
|
CommandCounterIncrement();
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* If the namespace already exists, clean it out (in case the
|
|
* former owner crashed without doing so).
|
|
*/
|
|
RemoveTempRelations(namespaceId);
|
|
}
|
|
|
|
/*
|
|
* Okay, we've prepared the temp namespace ... but it's not committed
|
|
* yet, so all our work could be undone by transaction rollback. Set
|
|
* flag for AtEOXact_Namespace to know what to do.
|
|
*/
|
|
myTempNamespace = namespaceId;
|
|
|
|
firstTempTransaction = true;
|
|
|
|
namespaceSearchPathValid = false; /* need to rebuild list */
|
|
}
|
|
|
|
/*
|
|
* End-of-transaction cleanup for namespaces.
|
|
*/
|
|
void
|
|
AtEOXact_Namespace(bool isCommit)
|
|
{
|
|
/*
|
|
* If we abort the transaction in which a temp namespace was selected,
|
|
* we'll have to do any creation or cleanout work over again. So,
|
|
* just forget the namespace entirely until next time. On the other
|
|
* hand, if we commit then register an exit callback to clean out the
|
|
* temp tables at backend shutdown. (We only want to register the
|
|
* callback once per session, so this is a good place to do it.)
|
|
*/
|
|
if (firstTempTransaction)
|
|
{
|
|
if (isCommit)
|
|
on_shmem_exit(RemoveTempRelationsCallback, 0);
|
|
else
|
|
{
|
|
myTempNamespace = InvalidOid;
|
|
namespaceSearchPathValid = false; /* need to rebuild list */
|
|
}
|
|
firstTempTransaction = false;
|
|
}
|
|
/*
|
|
* Clean up if someone failed to do PopSpecialNamespace
|
|
*/
|
|
if (OidIsValid(mySpecialNamespace))
|
|
{
|
|
mySpecialNamespace = InvalidOid;
|
|
namespaceSearchPathValid = false; /* need to rebuild list */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remove all relations in the specified temp namespace.
|
|
*
|
|
* This is called at backend shutdown (if we made any temp relations).
|
|
* It is also called when we begin using a pre-existing temp namespace,
|
|
* in order to clean out any relations that might have been created by
|
|
* a crashed backend.
|
|
*/
|
|
static void
|
|
RemoveTempRelations(Oid tempNamespaceId)
|
|
{
|
|
Relation pgclass;
|
|
HeapScanDesc scan;
|
|
HeapTuple tuple;
|
|
ScanKeyData key;
|
|
ObjectAddress object;
|
|
|
|
/*
|
|
* Scan pg_class to find all the relations in the target namespace.
|
|
* Ignore indexes, though, on the assumption that they'll go away
|
|
* when their tables are deleted.
|
|
*
|
|
* NOTE: if there are deletion constraints between temp relations,
|
|
* then our CASCADE delete call may cause as-yet-unvisited objects
|
|
* to go away. This is okay because we are using SnapshotNow; when
|
|
* the scan does reach those pg_class tuples, they'll be ignored as
|
|
* already deleted.
|
|
*/
|
|
ScanKeyEntryInitialize(&key, 0x0,
|
|
Anum_pg_class_relnamespace,
|
|
F_OIDEQ,
|
|
ObjectIdGetDatum(tempNamespaceId));
|
|
|
|
pgclass = heap_openr(RelationRelationName, AccessShareLock);
|
|
scan = heap_beginscan(pgclass, SnapshotNow, 1, &key);
|
|
|
|
while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
|
|
{
|
|
switch (((Form_pg_class) GETSTRUCT(tuple))->relkind)
|
|
{
|
|
case RELKIND_RELATION:
|
|
case RELKIND_SEQUENCE:
|
|
case RELKIND_VIEW:
|
|
AssertTupleDescHasOid(pgclass->rd_att);
|
|
object.classId = RelOid_pg_class;
|
|
object.objectId = HeapTupleGetOid(tuple);
|
|
object.objectSubId = 0;
|
|
performDeletion(&object, DROP_CASCADE);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
heap_endscan(scan);
|
|
heap_close(pgclass, AccessShareLock);
|
|
}
|
|
|
|
/*
|
|
* Callback to remove temp relations at backend exit.
|
|
*/
|
|
static void
|
|
RemoveTempRelationsCallback(void)
|
|
{
|
|
if (OidIsValid(myTempNamespace)) /* should always be true */
|
|
{
|
|
/* Need to ensure we have a usable transaction. */
|
|
AbortOutOfAnyTransaction();
|
|
StartTransactionCommand();
|
|
|
|
RemoveTempRelations(myTempNamespace);
|
|
|
|
CommitTransactionCommand();
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Routines for handling the GUC variable 'search_path'.
|
|
*/
|
|
|
|
/* assign_hook: validate new search_path, do extra actions as needed */
|
|
const char *
|
|
assign_search_path(const char *newval, bool doit, bool interactive)
|
|
{
|
|
char *rawname;
|
|
List *namelist;
|
|
List *l;
|
|
|
|
/* Need a modifiable copy of string */
|
|
rawname = pstrdup(newval);
|
|
|
|
/* Parse string into list of identifiers */
|
|
if (!SplitIdentifierString(rawname, ',', &namelist))
|
|
{
|
|
/* syntax error in name list */
|
|
pfree(rawname);
|
|
freeList(namelist);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* If we aren't inside a transaction, we cannot do database access so
|
|
* cannot verify the individual names. Must accept the list on faith.
|
|
*/
|
|
if (interactive && IsTransactionState())
|
|
{
|
|
/*
|
|
* Verify that all the names are either valid namespace names or
|
|
* "$user". We do not require $user to correspond to a valid
|
|
* namespace. We do not check for USAGE rights, either; should we?
|
|
*/
|
|
foreach(l, namelist)
|
|
{
|
|
char *curname = (char *) lfirst(l);
|
|
|
|
if (strcmp(curname, "$user") == 0)
|
|
continue;
|
|
if (!SearchSysCacheExists(NAMESPACENAME,
|
|
CStringGetDatum(curname),
|
|
0, 0, 0))
|
|
elog(ERROR, "Namespace \"%s\" does not exist", curname);
|
|
}
|
|
}
|
|
|
|
pfree(rawname);
|
|
freeList(namelist);
|
|
|
|
/*
|
|
* We mark the path as needing recomputation, but don't do anything until
|
|
* it's needed. This avoids trying to do database access during GUC
|
|
* initialization.
|
|
*/
|
|
if (doit)
|
|
namespaceSearchPathValid = false;
|
|
|
|
return newval;
|
|
}
|
|
|
|
/*
|
|
* InitializeSearchPath: initialize module during InitPostgres.
|
|
*
|
|
* This is called after we are up enough to be able to do catalog lookups.
|
|
*/
|
|
void
|
|
InitializeSearchPath(void)
|
|
{
|
|
if (IsBootstrapProcessingMode())
|
|
{
|
|
/*
|
|
* In bootstrap mode, the search path must be 'pg_catalog' so that
|
|
* tables are created in the proper namespace; ignore the GUC setting.
|
|
*/
|
|
MemoryContext oldcxt;
|
|
|
|
oldcxt = MemoryContextSwitchTo(TopMemoryContext);
|
|
namespaceSearchPath = makeListi1(PG_CATALOG_NAMESPACE);
|
|
MemoryContextSwitchTo(oldcxt);
|
|
defaultCreationNamespace = PG_CATALOG_NAMESPACE;
|
|
firstExplicitNamespace = PG_CATALOG_NAMESPACE;
|
|
namespaceSearchPathValid = true;
|
|
namespaceUser = GetUserId();
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* In normal mode, arrange for a callback on any syscache invalidation
|
|
* of pg_namespace rows.
|
|
*/
|
|
CacheRegisterSyscacheCallback(NAMESPACEOID,
|
|
NamespaceCallback,
|
|
(Datum) 0);
|
|
/* Force search path to be recomputed on next use */
|
|
namespaceSearchPathValid = false;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* NamespaceCallback
|
|
* Syscache inval callback function
|
|
*/
|
|
static void
|
|
NamespaceCallback(Datum arg, Oid relid)
|
|
{
|
|
/* Force search path to be recomputed on next use */
|
|
namespaceSearchPathValid = false;
|
|
}
|
|
|
|
/*
|
|
* Fetch the active search path, expressed as a List of OIDs.
|
|
*
|
|
* The returned list includes the implicitly-prepended namespaces only if
|
|
* includeImplicit is true.
|
|
*
|
|
* NB: caller must treat the list as read-only!
|
|
*/
|
|
List *
|
|
fetch_search_path(bool includeImplicit)
|
|
{
|
|
List *result;
|
|
|
|
recomputeNamespacePath();
|
|
|
|
result = namespaceSearchPath;
|
|
if (!includeImplicit)
|
|
{
|
|
while (result && (Oid) lfirsti(result) != firstExplicitNamespace)
|
|
result = lnext(result);
|
|
}
|
|
|
|
return result;
|
|
}
|