Fix bugs in relpersistence handling during table creation.

Unlike the relistemp field which it replaced, relpersistence must be
set correctly quite early during the table creation process, as we
rely on it quite early on for a number of purposes, including security
checks.  Normally, this is set based on whether the user enters CREATE
TABLE, CREATE UNLOGGED TABLE, or CREATE TEMPORARY TABLE, but a
relation may also be made implicitly temporary by creating it in
pg_temp.  This patch fixes the handling of that case, and also
disables creation of unlogged tables in temporary tablespace (such
table indeed skip WAL-logging, but we reject an explicit
specification) and creation of relations in the temporary schemas of
other sessions (which is not very sensible, and didn't work right
anyway).

Report by Amit Khandekar.

src/backend/catalog/namespace.c

@@ -311,19 +311,6 @@ RangeVarGetCreationNamespace(const RangeVar *newRelation)
 							newRelation->relname)));
 	}
 
-	if (newRelation->relpersistence == RELPERSISTENCE_TEMP)
-	{
-		/* TEMP tables are created in our backend-local temp namespace */
-		if (newRelation->schemaname)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
-				   errmsg("temporary tables cannot specify a schema name")));
-		/* Initialize temp namespace if first time through */
-		if (!OidIsValid(myTempNamespace))
-			InitTempTableNamespace();
-		return myTempNamespace;
-	}
-
 	if (newRelation->schemaname)
 	{
 		/* check for pg_temp alias */
@@ -338,6 +325,13 @@ RangeVarGetCreationNamespace(const RangeVar *newRelation)
 		namespaceId = get_namespace_oid(newRelation->schemaname, false);
 		/* we do not check for USAGE rights here! */
 	}
+	else if (newRelation->relpersistence == RELPERSISTENCE_TEMP)
+	{
+		/* Initialize temp namespace if first time through */
+		if (!OidIsValid(myTempNamespace))
+			InitTempTableNamespace();
+		return myTempNamespace;
+	}
 	else
 	{
 		/* use the default creation namespace */
@@ -389,6 +383,43 @@ RangeVarGetAndCheckCreationNamespace(const RangeVar *newRelation)
 	return namespaceId;
 }
 
+/*
+ * Adjust the relpersistence for an about-to-be-created relation based on the
+ * creation namespace, and throw an error for invalid combinations.
+ */
+void
+RangeVarAdjustRelationPersistence(RangeVar *newRelation, Oid nspid)
+{
+	switch (newRelation->relpersistence)
+	{
+		case RELPERSISTENCE_TEMP:
+			if (!isTempOrToastNamespace(nspid))
+			{
+				if (isAnyTempNamespace(nspid))
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+							 errmsg("cannot create relations in temporary schemas of other sessions")));
+				else
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+							 errmsg("cannot create temporary relation in non-temporary schema")));
+			}
+			break;
+		case RELPERSISTENCE_PERMANENT:
+			if (isTempOrToastNamespace(nspid))
+				newRelation->relpersistence = RELPERSISTENCE_TEMP;
+			else if (isAnyTempNamespace(nspid))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("cannot create relations in temporary schemas of other sessions")));
+			break;
+		default:
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+					 errmsg("only temporary relations may be created in temporary schemas")));
+	}
+}
+
 /*
  * RelnameGetRelid
  *		Try to resolve an unqualified relation name.

src/backend/commands/tablecmds.c

@@ -431,6 +431,13 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId)
 				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
 				 errmsg("constraints on foreign tables are not supported")));
 
+	/*
+	 * Look up the namespace in which we are supposed to create the relation,
+	 * and check we have permission to create there.
+	 */
+	namespaceId = RangeVarGetAndCheckCreationNamespace(stmt->relation);
+	RangeVarAdjustRelationPersistence(stmt->relation, namespaceId);
+
 	/*
 	 * Security check: disallow creating temp tables from security-restricted
 	 * code.  This is needed because calling code might not expect untrusted
@@ -442,12 +449,6 @@ DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId)
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 				 errmsg("cannot create temporary table within security-restricted operation")));
 
-	/*
-	 * Look up the namespace in which we are supposed to create the relation,
-	 * and check we have permission to create there.
-	 */
-	namespaceId = RangeVarGetAndCheckCreationNamespace(stmt->relation);
-
 	/*
 	 * Select tablespace to use.  If not specified, use default tablespace
 	 * (which may in turn default to database's default).

src/backend/commands/typecmds.c

@@ -1610,6 +1610,7 @@ DefineCompositeType(const RangeVar *typevar, List *coldeflist)
 	 * instead of below about a "relation".
 	 */
 	typeNamespace = RangeVarGetCreationNamespace(createStmt->relation);
+	RangeVarAdjustRelationPersistence(createStmt->relation, typeNamespace);
 	old_type_oid =
 		GetSysCacheOid2(TYPENAMENSP,
 						CStringGetDatum(createStmt->relation->relname),

src/backend/commands/view.c

@@ -97,10 +97,10 @@ isViewOnTempTable_walker(Node *node, void *context)
  *---------------------------------------------------------------------
  */
 static Oid
-DefineVirtualRelation(const RangeVar *relation, List *tlist, bool replace)
+DefineVirtualRelation(const RangeVar *relation, List *tlist, bool replace,
+					  Oid namespaceId)
 {
-	Oid			viewOid,
-				namespaceId;
+	Oid			viewOid;
 	CreateStmt *createStmt = makeNode(CreateStmt);
 	List	   *attrList;
 	ListCell   *t;
@@ -160,7 +160,6 @@ DefineVirtualRelation(const RangeVar *relation, List *tlist, bool replace)
 	/*
 	 * Check to see if we want to replace an existing view.
 	 */
-	namespaceId = RangeVarGetCreationNamespace(relation);
 	viewOid = get_relname_relid(relation->relname, namespaceId);
 
 	if (OidIsValid(viewOid) && replace)
@@ -417,6 +416,7 @@ DefineView(ViewStmt *stmt, const char *queryString)
 {
 	Query	   *viewParse;
 	Oid			viewOid;
+	Oid			namespaceId;
 	RangeVar   *view;
 
 	/*
@@ -480,28 +480,31 @@ DefineView(ViewStmt *stmt, const char *queryString)
 							"names than columns")));
 	}
 
+	/* Unlogged views are not sensible. */
+	if (stmt->view->relpersistence == RELPERSISTENCE_UNLOGGED)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+		errmsg("views cannot be unlogged because they do not have storage")));
+
 	/*
 	 * If the user didn't explicitly ask for a temporary view, check whether
 	 * we need one implicitly.	We allow TEMP to be inserted automatically as
 	 * long as the CREATE command is consistent with that --- no explicit
 	 * schema name.
 	 */
-	view = stmt->view;
+	view = copyObject(stmt->view);  /* don't corrupt original command */
 	if (view->relpersistence == RELPERSISTENCE_PERMANENT
 		&& isViewOnTempTable(viewParse))
 	{
-		view = copyObject(view);	/* don't corrupt original command */
 		view->relpersistence = RELPERSISTENCE_TEMP;
 		ereport(NOTICE,
 				(errmsg("view \"%s\" will be a temporary view",
 						view->relname)));
 	}
 
-	/* Unlogged views are not sensible. */
-	if (view->relpersistence == RELPERSISTENCE_UNLOGGED)
-		ereport(ERROR,
-				(errcode(ERRCODE_SYNTAX_ERROR),
-		errmsg("views cannot be unlogged because they do not have storage")));
+	/* Might also need to make it temporary if placed in temp schema. */
+	namespaceId = RangeVarGetCreationNamespace(view);
+	RangeVarAdjustRelationPersistence(view, namespaceId);
 
 	/*
 	 * Create the view relation
@@ -510,7 +513,7 @@ DefineView(ViewStmt *stmt, const char *queryString)
 	 * aborted.
 	 */
 	viewOid = DefineVirtualRelation(view, viewParse->targetList,
-									stmt->replace);
+									stmt->replace, namespaceId);
 
 	/*
 	 * The relation we have just created is not visible to any other commands

src/backend/executor/execMain.c

@@ -2413,6 +2413,13 @@ OpenIntoRel(QueryDesc *queryDesc)
 				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
 				 errmsg("ON COMMIT can only be used on temporary tables")));
 
+	/*
+	 * Find namespace to create in, check its permissions
+	 */
+	intoName = into->rel->relname;
+	namespaceId = RangeVarGetAndCheckCreationNamespace(into->rel);
+	RangeVarAdjustRelationPersistence(into->rel, namespaceId);
+
 	/*
 	 * Security check: disallow creating temp tables from security-restricted
 	 * code.  This is needed because calling code might not expect untrusted
@@ -2424,12 +2431,6 @@ OpenIntoRel(QueryDesc *queryDesc)
 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
 				 errmsg("cannot create temporary table within security-restricted operation")));
 
-	/*
-	 * Find namespace to create in, check its permissions
-	 */
-	intoName = into->rel->relname;
-	namespaceId = RangeVarGetAndCheckCreationNamespace(into->rel);
-
 	/*
 	 * Select tablespace to use.  If not specified, use default tablespace
 	 * (which may in turn default to database's default).

src/backend/parser/parse_utilcmd.c

@@ -162,6 +162,7 @@ transformCreateStmt(CreateStmt *stmt, const char *queryString)
 	 * possible.
 	 */
 	namespaceid = RangeVarGetAndCheckCreationNamespace(stmt->relation);
+	RangeVarAdjustRelationPersistence(stmt->relation, namespaceid);
 
 	/*
 	 * If the relation already exists and the user specified "IF NOT EXISTS",
@@ -374,7 +375,10 @@ transformColumnDefinition(CreateStmtContext *cxt, ColumnDef *column)
 		if (cxt->rel)
 			snamespaceid = RelationGetNamespace(cxt->rel);
 		else
+		{
 			snamespaceid = RangeVarGetCreationNamespace(cxt->relation);
+			RangeVarAdjustRelationPersistence(cxt->relation, snamespaceid);
+		}
 		snamespace = get_namespace_name(snamespaceid);
 		sname = ChooseRelationName(cxt->relation->relname,
 								   column->colname,

src/include/catalog/namespace.h

@@ -50,6 +50,7 @@ typedef struct OverrideSearchPath
 extern Oid	RangeVarGetRelid(const RangeVar *relation, bool failOK);
 extern Oid	RangeVarGetCreationNamespace(const RangeVar *newRelation);
 extern Oid	RangeVarGetAndCheckCreationNamespace(const RangeVar *newRelation);
+extern void RangeVarAdjustRelationPersistence(RangeVar *newRelation, Oid nspid);
 extern Oid	RelnameGetRelid(const char *relname);
 extern bool RelationIsVisible(Oid relid);
 

src/test/regress/expected/create_view.out

@@ -81,11 +81,11 @@ CREATE VIEW temp_view_test.v2 AS SELECT * FROM base_table;
 -- should fail
 CREATE VIEW temp_view_test.v3_temp AS SELECT * FROM temp_table;
 NOTICE:  view "v3_temp" will be a temporary view
-ERROR:  temporary tables cannot specify a schema name
+ERROR:  cannot create temporary relation in non-temporary schema
 -- should fail
 CREATE SCHEMA test_schema
     CREATE TEMP VIEW testview AS SELECT 1;
-ERROR:  temporary tables cannot specify a schema name
+ERROR:  cannot create temporary relation in non-temporary schema
 -- joins: if any of the join relations are temporary, the view
 -- should also be temporary
 -- should be non-temp