Propagate ALTER TYPE operations to typed tables

This adds RESTRICT/CASCADE flags to ALTER TYPE ... ADD/DROP/ALTER/
RENAME ATTRIBUTE to control whether to alter typed tables as well.

doc/src/sgml/ref/alter_type.sgml

@@ -26,15 +26,15 @@ PostgreSQL documentation
 ALTER TYPE <replaceable class="PARAMETER">name</replaceable> <replaceable class="PARAMETER">action</replaceable> [, ... ]
 ALTER TYPE <replaceable class="PARAMETER">name</replaceable> OWNER TO <replaceable class="PARAMETER">new_owner</replaceable>
 ALTER TYPE <replaceable class="PARAMETER">name</replaceable> RENAME ATTRIBUTE <replaceable class="PARAMETER">attribute_name</replaceable> TO <replaceable class="PARAMETER">new_attribute_name</replaceable>
-ALTER TYPE <replaceable class="PARAMETER">name</replaceable> RENAME TO <replaceable class="PARAMETER">new_name</replaceable>
+ALTER TYPE <replaceable class="PARAMETER">name</replaceable> RENAME TO <replaceable class="PARAMETER">new_name</replaceable> [ CASCADE | RESTRICT ]
 ALTER TYPE <replaceable class="PARAMETER">name</replaceable> SET SCHEMA <replaceable class="PARAMETER">new_schema</replaceable>
 ALTER TYPE <replaceable class="PARAMETER">name</replaceable> ADD VALUE <replaceable class="PARAMETER">new_enum_value</replaceable> [ { BEFORE | AFTER } <replaceable class="PARAMETER">existing_enum_value</replaceable> ]
 
 <phrase>where <replaceable class="PARAMETER">action</replaceable> is one of:</phrase>
 
-    ADD ATTRIBUTE <replaceable class="PARAMETER">attribute_name</replaceable> <replaceable class="PARAMETER">data_type</replaceable>
-    DROP ATTRIBUTE [ IF EXISTS ] <replaceable class="PARAMETER">attribute_name</replaceable>
-    ALTER ATTRIBUTE <replaceable class="PARAMETER">attribute_name</replaceable> [ SET DATA ] TYPE <replaceable class="PARAMETER">data_type</replaceable>
+    ADD ATTRIBUTE <replaceable class="PARAMETER">attribute_name</replaceable> <replaceable class="PARAMETER">data_type</replaceable> [ CASCADE | RESTRICT ]
+    DROP ATTRIBUTE [ IF EXISTS ] <replaceable class="PARAMETER">attribute_name</replaceable> [ CASCADE | RESTRICT ]
+    ALTER ATTRIBUTE <replaceable class="PARAMETER">attribute_name</replaceable> [ SET DATA ] TYPE <replaceable class="PARAMETER">data_type</replaceable> [ CASCADE | RESTRICT ]
 </synopsis>
  </refsynopsisdiv>
 
@@ -116,6 +116,26 @@ ALTER TYPE <replaceable class="PARAMETER">name</replaceable> ADD VALUE <replacea
      </para>
     </listitem>
    </varlistentry>
+
+   <varlistentry>
+    <term><literal>CASCADE</literal></term>
+    <listitem>
+     <para>
+      Automatically propagate the operation to typed tables of the
+      type being altered.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term><literal>RESTRICT</literal></term>
+    <listitem>
+     <para>
+      Refuse the operation if the type being altered is the type of a
+      typed table.  This is the default.
+     </para>
+    </listitem>
+   </varlistentry>
   </variablelist>
   </para>
 

src/backend/commands/alter.c

@@ -125,11 +125,7 @@ ExecRenameStmt(RenameStmt *stmt)
 						}
 					case OBJECT_COLUMN:
 					case OBJECT_ATTRIBUTE:
-						renameatt(relid,
-								  stmt->subname,		/* old att name */
-								  stmt->newname,		/* new att name */
-								  interpretInhOption(stmt->relation->inhOpt),	/* recursive? */
-								  0);	/* expected inhcount */
+						renameatt(relid, stmt);
 						break;
 					case OBJECT_TRIGGER:
 						renametrig(relid,

src/backend/nodes/copyfuncs.c

@@ -2803,6 +2803,7 @@ _copyRenameStmt(RenameStmt *from)
 	COPY_NODE_FIELD(objarg);
 	COPY_STRING_FIELD(subname);
 	COPY_STRING_FIELD(newname);
+	COPY_SCALAR_FIELD(behavior);
 
 	return newnode;
 }

src/backend/nodes/equalfuncs.c

@@ -1306,6 +1306,7 @@ _equalRenameStmt(RenameStmt *a, RenameStmt *b)
 	COMPARE_NODE_FIELD(objarg);
 	COMPARE_STRING_FIELD(subname);
 	COMPARE_STRING_FIELD(newname);
+	COMPARE_SCALAR_FIELD(behavior);
 
 	return true;
 }

src/backend/parser/gram.y

@@ -2003,41 +2003,43 @@ alter_type_cmds:
 		;
 
 alter_type_cmd:
-			/* ALTER TYPE <name> ADD ATTRIBUTE <coldef> */
-			ADD_P ATTRIBUTE TableFuncElement
+			/* ALTER TYPE <name> ADD ATTRIBUTE <coldef> [RESTRICT|CASCADE] */
+			ADD_P ATTRIBUTE TableFuncElement opt_drop_behavior
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
 					n->subtype = AT_AddColumn;
 					n->def = $3;
+					n->behavior = $4;
 					$$ = (Node *)n;
 				}
-			/* ALTER TYPE <name> DROP ATTRIBUTE IF EXISTS <attname> */
-			| DROP ATTRIBUTE IF_P EXISTS ColId
+			/* ALTER TYPE <name> DROP ATTRIBUTE IF EXISTS <attname> [RESTRICT|CASCADE] */
+			| DROP ATTRIBUTE IF_P EXISTS ColId opt_drop_behavior
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
 					n->subtype = AT_DropColumn;
 					n->name = $5;
-					n->behavior = DROP_RESTRICT; /* currently no effect */
+					n->behavior = $6;
 					n->missing_ok = TRUE;
 					$$ = (Node *)n;
 				}
-			/* ALTER TYPE <name> DROP ATTRIBUTE <attname> */
+			/* ALTER TYPE <name> DROP ATTRIBUTE <attname> [RESTRICT|CASCADE] */
 			| DROP ATTRIBUTE ColId opt_drop_behavior
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
 					n->subtype = AT_DropColumn;
 					n->name = $3;
-					n->behavior = DROP_RESTRICT; /* currently no effect */
+					n->behavior = $4;
 					n->missing_ok = FALSE;
 					$$ = (Node *)n;
 				}
-			/* ALTER TYPE <name> ALTER ATTRIBUTE <attname> [SET DATA] TYPE <typename> */
-			| ALTER ATTRIBUTE ColId opt_set_data TYPE_P Typename
+			/* ALTER TYPE <name> ALTER ATTRIBUTE <attname> [SET DATA] TYPE <typename> [RESTRICT|CASCADE] */
+			| ALTER ATTRIBUTE ColId opt_set_data TYPE_P Typename opt_drop_behavior
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
 					n->subtype = AT_AlterColumnType;
 					n->name = $3;
 					n->def = (Node *) $6;
+					n->behavior = $7;
 					$$ = (Node *)n;
 				}
 		;
@@ -6005,13 +6007,14 @@ RenameStmt: ALTER AGGREGATE func_name aggr_args RENAME TO name
 					n->newname = $6;
 					$$ = (Node *)n;
 				}
-			| ALTER TYPE_P any_name RENAME ATTRIBUTE name TO name
+			| ALTER TYPE_P any_name RENAME ATTRIBUTE name TO name opt_drop_behavior
 				{
 					RenameStmt *n = makeNode(RenameStmt);
 					n->renameType = OBJECT_ATTRIBUTE;
 					n->relation = makeRangeVarFromAnyName($3, @3, yyscanner);
 					n->subname = $6;
 					n->newname = $8;
+					n->behavior = $9;
 					$$ = (Node *)n;
 				}
 		;

src/include/commands/tablecmds.h

@@ -42,11 +42,7 @@ extern void CheckTableNotInUse(Relation rel, const char *stmt);
 
 extern void ExecuteTruncate(TruncateStmt *stmt);
 
-extern void renameatt(Oid myrelid,
-		  const char *oldattname,
-		  const char *newattname,
-		  bool recurse,
-		  int expected_parents);
+extern void renameatt(Oid myrelid, RenameStmt *stmt);
 
 extern void RenameRelation(Oid myrelid,
 			   const char *newrelname,

src/include/nodes/parsenodes.h

@@ -2073,6 +2073,7 @@ typedef struct RenameStmt
 	char	   *subname;		/* name of contained object (column, rule,
 								 * trigger, etc) */
 	char	   *newname;		/* the new name */
+	DropBehavior behavior;		/* RESTRICT or CASCADE behavior */
 } RenameStmt;
 
 /* ----------------------

src/test/regress/expected/alter_table.out

@@ -1760,13 +1760,100 @@ ALTER TYPE test_type1 ALTER ATTRIBUTE b TYPE varchar; -- fails
 ERROR:  cannot alter type "test_type1" because column "test_tbl1"."y" uses it
 CREATE TYPE test_type2 AS (a int, b text);
 CREATE TABLE test_tbl2 OF test_type2;
+\d test_type2
+Composite type "public.test_type2"
+ Column |  Type   
+--------+---------
+ a      | integer
+ b      | text
+
+\d test_tbl2
+   Table "public.test_tbl2"
+ Column |  Type   | Modifiers 
+--------+---------+-----------
+ a      | integer | 
+ b      | text    | 
+Typed table of type: test_type2
+
 ALTER TYPE test_type2 ADD ATTRIBUTE c text; -- fails
 ERROR:  cannot alter type "test_type2" because it is the type of a typed table
+HINT:  Use ALTER ... CASCADE to alter the typed tables too.
+ALTER TYPE test_type2 ADD ATTRIBUTE c text CASCADE;
+\d test_type2
+Composite type "public.test_type2"
+ Column |  Type   
+--------+---------
+ a      | integer
+ b      | text
+ c      | text
+
+\d test_tbl2
+   Table "public.test_tbl2"
+ Column |  Type   | Modifiers 
+--------+---------+-----------
+ a      | integer | 
+ b      | text    | 
+ c      | text    | 
+Typed table of type: test_type2
+
 ALTER TYPE test_type2 ALTER ATTRIBUTE b TYPE varchar; -- fails
 ERROR:  cannot alter type "test_type2" because it is the type of a typed table
+HINT:  Use ALTER ... CASCADE to alter the typed tables too.
+ALTER TYPE test_type2 ALTER ATTRIBUTE b TYPE varchar CASCADE;
+\d test_type2
+Composite type "public.test_type2"
+ Column |       Type        
+--------+-------------------
+ a      | integer
+ b      | character varying
+ c      | text
+
+\d test_tbl2
+        Table "public.test_tbl2"
+ Column |       Type        | Modifiers 
+--------+-------------------+-----------
+ a      | integer           | 
+ b      | character varying | 
+ c      | text              | 
+Typed table of type: test_type2
+
 ALTER TYPE test_type2 DROP ATTRIBUTE b; -- fails
 ERROR:  cannot alter type "test_type2" because it is the type of a typed table
-ALTER TYPE test_type2 RENAME ATTRIBUTE b TO bb; -- fails
+HINT:  Use ALTER ... CASCADE to alter the typed tables too.
+ALTER TYPE test_type2 DROP ATTRIBUTE b CASCADE;
+\d test_type2
+Composite type "public.test_type2"
+ Column |  Type   
+--------+---------
+ a      | integer
+ c      | text
+
+\d test_tbl2
+   Table "public.test_tbl2"
+ Column |  Type   | Modifiers 
+--------+---------+-----------
+ a      | integer | 
+ c      | text    | 
+Typed table of type: test_type2
+
+ALTER TYPE test_type2 RENAME ATTRIBUTE a TO aa; -- fails
 ERROR:  cannot alter type "test_type2" because it is the type of a typed table
+HINT:  Use ALTER ... CASCADE to alter the typed tables too.
+ALTER TYPE test_type2 RENAME ATTRIBUTE a TO aa CASCADE;
+\d test_type2
+Composite type "public.test_type2"
+ Column |  Type   
+--------+---------
+ aa     | integer
+ c      | text
+
+\d test_tbl2
+   Table "public.test_tbl2"
+ Column |  Type   | Modifiers 
+--------+---------+-----------
+ aa     | integer | 
+ c      | text    | 
+Typed table of type: test_type2
+
 CREATE TYPE test_type_empty AS ();
 DROP TYPE test_type_empty;

src/test/regress/sql/alter_table.sql

@@ -1272,10 +1272,28 @@ ALTER TYPE test_type1 ALTER ATTRIBUTE b TYPE varchar; -- fails
 
 CREATE TYPE test_type2 AS (a int, b text);
 CREATE TABLE test_tbl2 OF test_type2;
+\d test_type2
+\d test_tbl2
+
 ALTER TYPE test_type2 ADD ATTRIBUTE c text; -- fails
+ALTER TYPE test_type2 ADD ATTRIBUTE c text CASCADE;
+\d test_type2
+\d test_tbl2
+
 ALTER TYPE test_type2 ALTER ATTRIBUTE b TYPE varchar; -- fails
+ALTER TYPE test_type2 ALTER ATTRIBUTE b TYPE varchar CASCADE;
+\d test_type2
+\d test_tbl2
+
 ALTER TYPE test_type2 DROP ATTRIBUTE b; -- fails
-ALTER TYPE test_type2 RENAME ATTRIBUTE b TO bb; -- fails
+ALTER TYPE test_type2 DROP ATTRIBUTE b CASCADE;
+\d test_type2
+\d test_tbl2
+
+ALTER TYPE test_type2 RENAME ATTRIBUTE a TO aa; -- fails
+ALTER TYPE test_type2 RENAME ATTRIBUTE a TO aa CASCADE;
+\d test_type2
+\d test_tbl2
 
 CREATE TYPE test_type_empty AS ();
 DROP TYPE test_type_empty;