Rearrange ALTER TABLE syntax processing as per my recent proposal: the

grammar allows ALTER TABLE/INDEX/SEQUENCE/VIEW interchangeably for all
subforms of those commands, and then we sort out what's really legal
at execution time.  This allows the ALTER SEQUENCE/VIEW reference pages
to fully document all the ALTER forms available for sequences and views
respectively, and eliminates a longstanding cause of confusion for users.

The net effect is that the following forms are allowed that weren't before:
	ALTER SEQUENCE OWNER TO
	ALTER VIEW ALTER COLUMN SET/DROP DEFAULT
	ALTER VIEW OWNER TO
	ALTER VIEW SET SCHEMA
(There's no actual functionality gain here, but formerly you had to say
ALTER TABLE instead.)

Interestingly, the grammar tables actually get smaller, probably because
there are fewer special cases to keep track of.

I did not disallow using ALTER TABLE for these operations.  Perhaps we
should, but there's a backwards-compatibility issue if we do; in fact
it would break existing pg_dump scripts.  I did however tighten up
ALTER SEQUENCE and ALTER VIEW to reject non-sequences and non-views
in the new cases as well as a couple of cases where they didn't before.

The patch doesn't change pg_dump to use the new syntaxes, either.

5 files changed, 156 insertions, 61 deletions

diff --git a/src/backend/commands/alter.c b/src/backend/commands/alter.c
index 63acefa527d..fce328bcc40 100644
--- a/src/backend/commands/alter.c
+++ b/src/backend/commands/alter.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/alter.c,v 1.28 2008/03/19 18:38:30 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/alter.c,v 1.29 2008/06/15 01:25:53 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -185,8 +185,10 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt)
 
 		case OBJECT_SEQUENCE:
 		case OBJECT_TABLE:
+		case OBJECT_VIEW:
 			CheckRelationOwnership(stmt->relation, true);
-			AlterTableNamespace(stmt->relation, stmt->newschema);
+			AlterTableNamespace(stmt->relation, stmt->newschema,
+								stmt->objectType);
 			break;
 
 		case OBJECT_TYPE:
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 7f7102858b1..b3d21875b25 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.256 2008/06/14 18:04:33 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.257 2008/06/15 01:25:53 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2175,6 +2175,44 @@ AlterTable(AlterTableStmt *stmt)
 
 	CheckTableNotInUse(rel, "ALTER TABLE");
 
+	/* Check relation type against type specified in the ALTER command */
+	switch (stmt->relkind)
+	{
+		case OBJECT_TABLE:
+			/*
+			 * For mostly-historical reasons, we allow ALTER TABLE to apply
+			 * to all relation types.
+			 */
+			break;
+
+		case OBJECT_INDEX:
+			if (rel->rd_rel->relkind != RELKIND_INDEX)
+				ereport(ERROR,
+						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						 errmsg("\"%s\" is not an index",
+								RelationGetRelationName(rel))));
+			break;
+
+		case OBJECT_SEQUENCE:
+			if (rel->rd_rel->relkind != RELKIND_SEQUENCE)
+				ereport(ERROR,
+						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						 errmsg("\"%s\" is not a sequence",
+								RelationGetRelationName(rel))));
+			break;
+
+		case OBJECT_VIEW:
+			if (rel->rd_rel->relkind != RELKIND_VIEW)
+				ereport(ERROR,
+						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						 errmsg("\"%s\" is not a view",
+								RelationGetRelationName(rel))));
+			break;
+
+		default:
+			elog(ERROR, "unrecognized object type: %d", (int) stmt->relkind);
+	}
+
 	ATController(rel, stmt->cmds, interpretInhOption(stmt->relation->inhOpt));
 }
 
@@ -7191,7 +7229,8 @@ ATExecDropInherit(Relation rel, RangeVar *parent)
  * Note: caller must have checked ownership of the relation already
  */
 void
-AlterTableNamespace(RangeVar *relation, const char *newschema)
+AlterTableNamespace(RangeVar *relation, const char *newschema,
+					ObjectType stmttype)
 {
 	Relation	rel;
 	Oid			relid;
@@ -7204,6 +7243,36 @@ AlterTableNamespace(RangeVar *relation, const char *newschema)
 	relid = RelationGetRelid(rel);
 	oldNspOid = RelationGetNamespace(rel);
 
+	/* Check relation type against type specified in the ALTER command */
+	switch (stmttype)
+	{
+		case OBJECT_TABLE:
+			/*
+			 * For mostly-historical reasons, we allow ALTER TABLE to apply
+			 * to all relation types.
+			 */
+			break;
+
+		case OBJECT_SEQUENCE:
+			if (rel->rd_rel->relkind != RELKIND_SEQUENCE)
+				ereport(ERROR,
+						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						 errmsg("\"%s\" is not a sequence",
+								RelationGetRelationName(rel))));
+			break;
+
+		case OBJECT_VIEW:
+			if (rel->rd_rel->relkind != RELKIND_VIEW)
+				ereport(ERROR,
+						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						 errmsg("\"%s\" is not a view",
+								RelationGetRelationName(rel))));
+			break;
+
+		default:
+			elog(ERROR, "unrecognized object type: %d", (int) stmttype);
+	}
+
 	/* Can we change the schema of this tuple? */
 	switch (rel->rd_rel->relkind)
 	{
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 591920d6f68..4e59e37da91 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.615 2008/05/16 23:36:05 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.616 2008/06/15 01:25:54 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -185,8 +185,8 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
 %type <node>	alter_column_default opclass_item opclass_drop alter_using
 %type <ival>	add_drop opt_asc_desc opt_nulls_order
 
-%type <node>	alter_table_cmd alter_rel_cmd
-%type <list>	alter_table_cmds alter_rel_cmds
+%type <node>	alter_table_cmd
+%type <list>	alter_table_cmds
 
 %type <dbehavior>	opt_drop_behavior
 
@@ -291,8 +291,8 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
 
 %type <node>	fetch_direction select_limit_value select_offset_value
 
-%type <list>	OptSeqList
-%type <defelt>	OptSeqElem
+%type <list>	OptSeqOptList SeqOptList
+%type <defelt>	SeqOptElem
 
 %type <istmt>	insert_rest
 
@@ -1391,8 +1391,10 @@ DiscardStmt:
 
 /*****************************************************************************
  *
- *	ALTER [ TABLE | INDEX ] variations
+ *	ALTER [ TABLE | INDEX | SEQUENCE | VIEW ] variations
  *
+ * Note: we accept all subcommands for each of the four variants, and sort
+ * out what's really legal at execution time.
  *****************************************************************************/
 
 AlterTableStmt:
@@ -1404,7 +1406,7 @@ AlterTableStmt:
 					n->relkind = OBJECT_TABLE;
 					$$ = (Node *)n;
 				}
-		|	ALTER INDEX relation_expr alter_rel_cmds
+		|	ALTER INDEX relation_expr alter_table_cmds
 				{
 					AlterTableStmt *n = makeNode(AlterTableStmt);
 					n->relation = $3;
@@ -1412,6 +1414,22 @@ AlterTableStmt:
 					n->relkind = OBJECT_INDEX;
 					$$ = (Node *)n;
 				}
+		|	ALTER SEQUENCE relation_expr alter_table_cmds
+				{
+					AlterTableStmt *n = makeNode(AlterTableStmt);
+					n->relation = $3;
+					n->cmds = $4;
+					n->relkind = OBJECT_SEQUENCE;
+					$$ = (Node *)n;
+				}
+		|	ALTER VIEW relation_expr alter_table_cmds
+				{
+					AlterTableStmt *n = makeNode(AlterTableStmt);
+					n->relation = $3;
+					n->cmds = $4;
+					n->relkind = OBJECT_VIEW;
+					$$ = (Node *)n;
+				}
 		;
 
 alter_table_cmds:
@@ -1419,9 +1437,8 @@ alter_table_cmds:
 			| alter_table_cmds ',' alter_table_cmd	{ $$ = lappend($1, $3); }
 		;
 
-/* Subcommands that are for ALTER TABLE only */
 alter_table_cmd:
-			/* ALTER TABLE <relation> ADD [COLUMN] <coldef> */
+			/* ALTER TABLE <name> ADD [COLUMN] <coldef> */
 			ADD_P opt_column columnDef
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1429,7 +1446,7 @@ alter_table_cmd:
 					n->def = $3;
 					$$ = (Node *)n;
 				}
-			/* ALTER TABLE <relation> ALTER [COLUMN] <colname> {SET DEFAULT <expr>|DROP DEFAULT} */
+			/* ALTER TABLE <name> ALTER [COLUMN] <colname> {SET DEFAULT <expr>|DROP DEFAULT} */
 			| ALTER opt_column ColId alter_column_default
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1438,7 +1455,7 @@ alter_table_cmd:
 					n->def = $4;
 					$$ = (Node *)n;
 				}
-			/* ALTER TABLE <relation> ALTER [COLUMN] <colname> DROP NOT NULL */
+			/* ALTER TABLE <name> ALTER [COLUMN] <colname> DROP NOT NULL */
 			| ALTER opt_column ColId DROP NOT NULL_P
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1446,7 +1463,7 @@ alter_table_cmd:
 					n->name = $3;
 					$$ = (Node *)n;
 				}
-			/* ALTER TABLE <relation> ALTER [COLUMN] <colname> SET NOT NULL */
+			/* ALTER TABLE <name> ALTER [COLUMN] <colname> SET NOT NULL */
 			| ALTER opt_column ColId SET NOT NULL_P
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1454,7 +1471,7 @@ alter_table_cmd:
 					n->name = $3;
 					$$ = (Node *)n;
 				}
-			/* ALTER TABLE <relation> ALTER [COLUMN] <colname> SET STATISTICS <IntegerOnly> */
+			/* ALTER TABLE <name> ALTER [COLUMN] <colname> SET STATISTICS <IntegerOnly> */
 			| ALTER opt_column ColId SET STATISTICS IntegerOnly
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1463,7 +1480,7 @@ alter_table_cmd:
 					n->def = (Node *) $6;
 					$$ = (Node *)n;
 				}
-			/* ALTER TABLE <relation> ALTER [COLUMN] <colname> SET STORAGE <storagemode> */
+			/* ALTER TABLE <name> ALTER [COLUMN] <colname> SET STORAGE <storagemode> */
 			| ALTER opt_column ColId SET STORAGE ColId
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1472,7 +1489,7 @@ alter_table_cmd:
 					n->def = (Node *) makeString($6);
 					$$ = (Node *)n;
 				}
-			/* ALTER TABLE <relation> DROP [COLUMN] <colname> [RESTRICT|CASCADE] */
+			/* ALTER TABLE <name> DROP [COLUMN] <colname> [RESTRICT|CASCADE] */
 			| DROP opt_column ColId opt_drop_behavior
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1482,7 +1499,7 @@ alter_table_cmd:
 					$$ = (Node *)n;
 				}
 			/*
-			 * ALTER TABLE <relation> ALTER [COLUMN] <colname> TYPE <typename>
+			 * ALTER TABLE <name> ALTER [COLUMN] <colname> TYPE <typename>
 			 *		[ USING <expression> ]
 			 */
 			| ALTER opt_column ColId TYPE_P Typename alter_using
@@ -1494,7 +1511,7 @@ alter_table_cmd:
 					n->transform = $6;
 					$$ = (Node *)n;
 				}
-			/* ALTER TABLE <relation> ADD CONSTRAINT ... */
+			/* ALTER TABLE <name> ADD CONSTRAINT ... */
 			| ADD_P TableConstraint
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1502,7 +1519,7 @@ alter_table_cmd:
 					n->def = $2;
 					$$ = (Node *)n;
 				}
-			/* ALTER TABLE <relation> DROP CONSTRAINT <name> [RESTRICT|CASCADE] */
+			/* ALTER TABLE <name> DROP CONSTRAINT <name> [RESTRICT|CASCADE] */
 			| DROP CONSTRAINT name opt_drop_behavior
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1511,7 +1528,7 @@ alter_table_cmd:
 					n->behavior = $4;
 					$$ = (Node *)n;
 				}
-			/* ALTER TABLE <relation> SET WITHOUT OIDS  */
+			/* ALTER TABLE <name> SET WITHOUT OIDS  */
 			| SET WITHOUT OIDS
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1642,28 +1659,15 @@ alter_table_cmd:
 					n->def = (Node *) $3;
 					$$ = (Node *)n;
 				}
-			| alter_rel_cmd
-				{
-					$$ = $1;
-				}
-		;
-
-alter_rel_cmds:
-			alter_rel_cmd							{ $$ = list_make1($1); }
-			| alter_rel_cmds ',' alter_rel_cmd		{ $$ = lappend($1, $3); }
-		;
-
-/* Subcommands that are for ALTER TABLE or ALTER INDEX */
-alter_rel_cmd:
-			/* ALTER [TABLE|INDEX] <name> OWNER TO RoleId */
-			OWNER TO RoleId
+			/* ALTER TABLE <name> OWNER TO RoleId */
+			| OWNER TO RoleId
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
 					n->subtype = AT_ChangeOwner;
 					n->name = $3;
 					$$ = (Node *)n;
 				}
-			/* ALTER [TABLE|INDEX] <name> SET TABLESPACE <tablespacename> */
+			/* ALTER TABLE <name> SET TABLESPACE <tablespacename> */
 			| SET TABLESPACE name
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1671,7 +1675,7 @@ alter_rel_cmd:
 					n->name = $3;
 					$$ = (Node *)n;
 				}
-			/* ALTER [TABLE|INDEX] <name> SET (...) */
+			/* ALTER TABLE <name> SET (...) */
 			| SET definition
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -1679,7 +1683,7 @@ alter_rel_cmd:
 					n->def = (Node *)$2;
 					$$ = (Node *)n;
 				}
-			/* ALTER [TABLE|INDEX] <name> RESET (...) */
+			/* ALTER TABLE <name> RESET (...) */
 			| RESET definition
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -2425,7 +2429,7 @@ CreateAsElement:
  *****************************************************************************/
 
 CreateSeqStmt:
-			CREATE OptTemp SEQUENCE qualified_name OptSeqList
+			CREATE OptTemp SEQUENCE qualified_name OptSeqOptList
 				{
 					CreateSeqStmt *n = makeNode(CreateSeqStmt);
 					$4->istemp = $2;
@@ -2436,7 +2440,7 @@ CreateSeqStmt:
 		;
 
 AlterSeqStmt:
-			ALTER SEQUENCE qualified_name OptSeqList
+			ALTER SEQUENCE relation_expr SeqOptList
 				{
 					AlterSeqStmt *n = makeNode(AlterSeqStmt);
 					n->sequence = $3;
@@ -2445,11 +2449,15 @@ AlterSeqStmt:
 				}
 		;
 
-OptSeqList: OptSeqList OptSeqElem					{ $$ = lappend($1, $2); }
+OptSeqOptList: SeqOptList							{ $$ = $1; }
 			| /*EMPTY*/								{ $$ = NIL; }
 		;
 
-OptSeqElem: CACHE NumericOnly
+SeqOptList: SeqOptElem								{ $$ = list_make1($1); }
+			| SeqOptList SeqOptElem					{ $$ = lappend($1, $2); }
+		;
+
+SeqOptElem: CACHE NumericOnly
 				{
 					$$ = makeDefElem("cache", (Node *)$2);
 				}
@@ -4802,6 +4810,14 @@ AlterObjectSchemaStmt:
 					n->newschema = $6;
 					$$ = (Node *)n;
 				}
+			| ALTER TABLE relation_expr SET SCHEMA name
+				{
+					AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
+					n->objectType = OBJECT_TABLE;
+					n->relation = $3;
+					n->newschema = $6;
+					$$ = (Node *)n;
+				}
 			| ALTER SEQUENCE relation_expr SET SCHEMA name
 				{
 					AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
@@ -4810,10 +4826,10 @@ AlterObjectSchemaStmt:
 					n->newschema = $6;
 					$$ = (Node *)n;
 				}
-			| ALTER TABLE relation_expr SET SCHEMA name
+			| ALTER VIEW relation_expr SET SCHEMA name
 				{
 					AlterObjectSchemaStmt *n = makeNode(AlterObjectSchemaStmt);
-					n->objectType = OBJECT_TABLE;
+					n->objectType = OBJECT_VIEW;
 					n->relation = $3;
 					n->newschema = $6;
 					$$ = (Node *)n;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 6c839650b43..1922ffc960d 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.293 2008/06/14 18:04:33 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.294 2008/06/15 01:25:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1454,6 +1454,9 @@ CreateCommandTag(Node *parsetree)
 				case OBJECT_TSCONFIGURATION:
 					tag = "ALTER TEXT SEARCH CONFIGURATION";
 					break;
+				case OBJECT_VIEW:
+					tag = "ALTER VIEW";
+					break;
 				default:
 					tag = "???";
 					break;
@@ -1512,19 +1515,23 @@ CreateCommandTag(Node *parsetree)
 			break;
 
 		case T_AlterTableStmt:
+			switch (((AlterTableStmt *) parsetree)->relkind)
 			{
-				AlterTableStmt *stmt = (AlterTableStmt *) parsetree;
-
-				/*
-				 * We might be supporting ALTER INDEX here, so set the
-				 * completion tag appropriately. Catch all other possibilities
-				 * with ALTER TABLE
-				 */
-
-				if (stmt->relkind == OBJECT_INDEX)
-					tag = "ALTER INDEX";
-				else
+				case OBJECT_TABLE:
 					tag = "ALTER TABLE";
+					break;
+				case OBJECT_INDEX:
+					tag = "ALTER INDEX";
+					break;
+				case OBJECT_SEQUENCE:
+					tag = "ALTER SEQUENCE";
+					break;
+				case OBJECT_VIEW:
+					tag = "ALTER VIEW";
+					break;
+				default:
+					tag = "???";
+					break;
 			}
 			break;
 
diff --git a/src/include/commands/tablecmds.h b/src/include/commands/tablecmds.h
index cdb80240169..d9e1a563728 100644
--- a/src/include/commands/tablecmds.h
+++ b/src/include/commands/tablecmds.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/commands/tablecmds.h,v 1.39 2008/06/14 18:04:34 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/commands/tablecmds.h,v 1.40 2008/06/15 01:25:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -28,7 +28,8 @@ extern void ATExecChangeOwner(Oid relationOid, Oid newOwnerId, bool recursing);
 
 extern void AlterTableInternal(Oid relid, List *cmds, bool recurse);
 
-extern void AlterTableNamespace(RangeVar *relation, const char *newschema);
+extern void AlterTableNamespace(RangeVar *relation, const char *newschema,
+								ObjectType stmttype);
 
 extern void AlterRelationNamespaceInternal(Relation classRel, Oid relOid,
 							   Oid oldNspOid, Oid newNspOid,