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/*-------------------------------------------------------------------------
*
* schemacmds.c
* schema creation/manipulation commands
*
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/schemacmds.c,v 1.6.2.1 2008/01/03 21:25:58 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/heapam.h"
#include "catalog/catalog.h"
#include "catalog/catname.h"
#include "catalog/dependency.h"
#include "catalog/namespace.h"
#include "catalog/pg_namespace.h"
#include "commands/schemacmds.h"
#include "miscadmin.h"
#include "parser/analyze.h"
#include "tcop/utility.h"
#include "utils/acl.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
/*
* CREATE SCHEMA
*/
void
CreateSchemaCommand(CreateSchemaStmt *stmt)
{
const char *schemaName = stmt->schemaname;
const char *authId = stmt->authid;
Oid namespaceId;
List *parsetree_list;
List *parsetree_item;
const char *owner_name;
Oid owner_userid;
Oid saved_userid;
bool saved_secdefcxt;
AclResult aclresult;
GetUserIdAndContext(&saved_userid, &saved_secdefcxt);
/*
* Figure out user identities.
*/
if (!authId)
{
owner_userid = saved_userid;
owner_name = GetUserNameFromId(owner_userid);
}
else if (superuser())
{
owner_name = authId;
/* The following will error out if user does not exist */
owner_userid = get_usesysid(owner_name);
/*
* Set the current user to the requested authorization so that
* objects created in the statement have the requested owner.
* (This will revert to session user on error or at the end of
* this routine.)
*/
SetUserIdAndContext(owner_userid, true);
}
else
/* not superuser */
{
owner_userid = saved_userid;
owner_name = GetUserNameFromId(owner_userid);
if (strcmp(authId, owner_name) != 0)
elog(ERROR, "CREATE SCHEMA: permission denied"
"\n\t\"%s\" is not a superuser, so cannot create a schema for \"%s\"",
owner_name, authId);
}
/*
* Permissions checks.
*/
aclresult = pg_database_aclcheck(MyDatabaseId, saved_userid, ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, DatabaseName);
if (!allowSystemTableMods && IsReservedName(schemaName))
elog(ERROR, "CREATE SCHEMA: Illegal schema name: \"%s\" -- pg_ is reserved for system schemas",
schemaName);
/* Create the schema's namespace */
namespaceId = NamespaceCreate(schemaName, owner_userid);
/* Advance cmd counter to make the namespace visible */
CommandCounterIncrement();
/*
* Temporarily make the new namespace be the front of the search path,
* as well as the default creation target namespace. This will be
* undone at the end of this routine, or upon error.
*/
PushSpecialNamespace(namespaceId);
/*
* Examine the list of commands embedded in the CREATE SCHEMA command,
* and reorganize them into a sequentially executable order with no
* forward references. Note that the result is still a list of raw
* parsetrees in need of parse analysis --- we cannot, in general, run
* analyze.c on one statement until we have actually executed the
* prior ones.
*/
parsetree_list = analyzeCreateSchemaStmt(stmt);
/*
* Analyze and execute each command contained in the CREATE SCHEMA
*/
foreach(parsetree_item, parsetree_list)
{
Node *parsetree = (Node *) lfirst(parsetree_item);
List *querytree_list,
*querytree_item;
querytree_list = parse_analyze(parsetree, NULL);
foreach(querytree_item, querytree_list)
{
Query *querytree = (Query *) lfirst(querytree_item);
/* schemas should contain only utility stmts */
Assert(querytree->commandType == CMD_UTILITY);
/* do this step */
ProcessUtility(querytree->utilityStmt, None, NULL);
/* make sure later steps can see the object created here */
CommandCounterIncrement();
}
}
/* Reset search path to normal state */
PopSpecialNamespace(namespaceId);
/* Reset current user */
SetUserIdAndContext(saved_userid, saved_secdefcxt);
}
/*
* RemoveSchema
* Removes a schema.
*/
void
RemoveSchema(List *names, DropBehavior behavior)
{
char *namespaceName;
Oid namespaceId;
ObjectAddress object;
if (length(names) != 1)
elog(ERROR, "Schema name may not be qualified");
namespaceName = strVal(lfirst(names));
namespaceId = GetSysCacheOid(NAMESPACENAME,
CStringGetDatum(namespaceName),
0, 0, 0);
if (!OidIsValid(namespaceId))
elog(ERROR, "Schema \"%s\" does not exist", namespaceName);
/* Permission check */
if (!pg_namespace_ownercheck(namespaceId, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, namespaceName);
/*
* Do the deletion. Objects contained in the schema are removed by
* means of their dependency links to the schema.
*
* XXX currently, index opclasses don't have creation/deletion commands,
* so they will not get removed when the containing schema is removed.
* This is annoying but not fatal.
*/
object.classId = get_system_catalog_relid(NamespaceRelationName);
object.objectId = namespaceId;
object.objectSubId = 0;
performDeletion(&object, behavior);
}
/*
* Guts of schema deletion.
*/
void
RemoveSchemaById(Oid schemaOid)
{
Relation relation;
HeapTuple tup;
relation = heap_openr(NamespaceRelationName, RowExclusiveLock);
tup = SearchSysCache(NAMESPACEOID,
ObjectIdGetDatum(schemaOid),
0, 0, 0);
if (!HeapTupleIsValid(tup))
elog(ERROR, "RemoveSchemaById: schema %u not found",
schemaOid);
simple_heap_delete(relation, &tup->t_self);
ReleaseSysCache(tup);
heap_close(relation, RowExclusiveLock);
}
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