Add attisinherited column to pg_attribute; use it to guard against

column additions, deletions, and renames that would let a child table
get out of sync with its parent.  Patch by Alvaro Herrera, with some
kibitzing by Tom Lane.

doc/src/sgml/catalogs.sgml

 <!--
  Documentation of the system catalogs, directed toward PostgreSQL developers
- $Header: /cvsroot/pgsql/doc/src/sgml/catalogs.sgml,v 2.55 2002/08/28 15:02:55 tgl Exp $
+ $Header: /cvsroot/pgsql/doc/src/sgml/catalogs.sgml,v 2.56 2002/08/30 19:23:18 tgl Exp $
  -->
 
 <chapter id="catalogs">
@@ -821,6 +821,16 @@
       </entry>
      </row>
 
+     <row>
+      <entry>attisinherited</entry>
+      <entry><type>bool</type></entry>
+      <entry></entry>
+      <entry>
+       This column is inherited from some other relation.  An inherited
+       column cannot be dropped nor renamed.
+      </entry>
+     </row>
+
     </tbody>
    </tgroup>
   </table>

src/backend/access/common/tupdesc.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/common/tupdesc.c,v 1.86 2002/08/29 00:17:02 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/common/tupdesc.c,v 1.87 2002/08/30 19:23:18 tgl Exp $
  *
  * NOTES
  *	  some of the executor utility code such as "ExecTypeFromTL" should be
@@ -231,6 +231,9 @@ FreeTupleDesc(TupleDesc tupdesc)
 
 }
 
+/*
+ * Compare two TupleDesc structures for logical equality
+ */
 bool
 equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
 {
@@ -264,8 +267,12 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
 			return false;
 		if (attr1->attnotnull != attr2->attnotnull)
 			return false;
+		if (attr1->atthasdef != attr2->atthasdef)
+			return false;
 		if (attr1->attisdropped != attr2->attisdropped)
 			return false;
+		if (attr1->attisinherited != attr2->attisinherited)
+			return false;
 	}
 	if (tupdesc1->constr != NULL)
 	{
@@ -389,6 +396,7 @@ TupleDescInitEntry(TupleDesc desc,
 	att->attnotnull = false;
 	att->atthasdef = false;
 	att->attisdropped = false;
+	att->attisinherited = false;
 
 	tuple = SearchSysCache(TYPEOID,
 						   ObjectIdGetDatum(oidtypeid),
@@ -514,7 +522,7 @@ BuildDescForRelation(List *schema)
 						   typenameTypeId(entry->typename),
 						   atttypmod, attdim, attisset);
 
-		/* This is for constraints */
+		/* Fill in additional stuff not handled by TupleDescInitEntry */
 		if (entry->is_not_null)
 			constr->has_not_null = true;
 		desc->attrs[attnum - 1]->attnotnull = entry->is_not_null;
@@ -533,7 +541,9 @@ BuildDescForRelation(List *schema)
 			desc->attrs[attnum - 1]->atthasdef = true;
 		}
 
+		desc->attrs[attnum - 1]->attisinherited = entry->is_inherited;
 	}
+
 	if (constr->has_not_null || ndef > 0)
 	{
 		desc->constr = constr;

src/backend/catalog/index.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.191 2002/08/29 15:56:19 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.192 2002/08/30 19:23:18 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -259,6 +259,7 @@ ConstructTupleDescriptor(Relation heapRelation,
 		to->attcacheoff = -1;
 		to->attnotnull = false;
 		to->atthasdef = false;
+		to->attisinherited = false;
 
 		/*
 		 * We do not yet have the correct relation OID for the index, so

src/backend/commands/sequence.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/sequence.c,v 1.84 2002/08/06 02:36:34 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/sequence.c,v 1.85 2002/08/30 19:23:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -127,6 +127,7 @@ DefineSequence(CreateSeqStmt *seq)
 
 		coldef = makeNode(ColumnDef);
 		coldef->typename = typnam;
+		coldef->is_inherited = false;
 		coldef->is_not_null = true;
 		coldef->raw_default = NULL;
 		coldef->cooked_default = NULL;

src/backend/commands/view.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$Id: view.c,v 1.67 2002/07/16 22:12:19 tgl Exp $
+ *	$Id: view.c,v 1.68 2002/08/30 19:23:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -68,6 +68,7 @@ DefineVirtualRelation(const RangeVar *relation, List *tlist)
 			typename->typmod = res->restypmod;
 			def->typename = typename;
 
+			def->is_inherited = false;
 			def->is_not_null = false;
 			def->raw_default = NULL;
 			def->cooked_default = NULL;

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.207 2002/08/27 04:55:07 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.208 2002/08/30 19:23:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1729,6 +1729,7 @@ _copyColumnDef(ColumnDef *from)
 	if (from->colname)
 		newnode->colname = pstrdup(from->colname);
 	Node_Copy(from, newnode, typename);
+	newnode->is_inherited = from->is_inherited;
 	newnode->is_not_null = from->is_not_null;
 	Node_Copy(from, newnode, raw_default);
 	if (from->cooked_default)

src/backend/nodes/equalfuncs.c

@@ -20,7 +20,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.155 2002/08/27 04:55:07 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.156 2002/08/30 19:23:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1748,6 +1748,8 @@ _equalColumnDef(ColumnDef *a, ColumnDef *b)
 		return false;
 	if (!equal(a->typename, b->typename))
 		return false;
+	if (a->is_inherited != b->is_inherited)
+		return false;
 	if (a->is_not_null != b->is_not_null)
 		return false;
 	if (!equal(a->raw_default, b->raw_default))

src/backend/nodes/outfuncs.c

@@ -5,7 +5,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$Header: /cvsroot/pgsql/src/backend/nodes/outfuncs.c,v 1.170 2002/08/29 00:17:04 tgl Exp $
+ *	$Header: /cvsroot/pgsql/src/backend/nodes/outfuncs.c,v 1.171 2002/08/30 19:23:19 tgl Exp $
  *
  * NOTES
  *	  Every (plan) node in POSTGRES has an associated "out" routine which
@@ -176,7 +176,8 @@ _outColumnDef(StringInfo str, ColumnDef *node)
 	_outToken(str, node->colname);
 	appendStringInfo(str, " :typename ");
 	_outNode(str, node->typename);
-	appendStringInfo(str, " :is_not_null %s :raw_default ",
+	appendStringInfo(str, " :is_inherited %s :is_not_null %s :raw_default ",
+					 booltostr(node->is_inherited),
 					 booltostr(node->is_not_null));
 	_outNode(str, node->raw_default);
 	appendStringInfo(str, " :cooked_default ");

src/backend/nodes/readfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.129 2002/08/26 17:53:58 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.130 2002/08/30 19:23:19 tgl Exp $
  *
  * NOTES
  *	  Most of the read functions for plan nodes are tested. (In fact, they
@@ -1485,6 +1485,10 @@ _readColumnDef(void)
 	token = pg_strtok(&length); /* eat :typename */
 	local_node->typename = nodeRead(true); /* now read it */
 
+	token = pg_strtok(&length); /* eat :is_inherited */
+	token = pg_strtok(&length); /* get :is_inherited */
+	local_node->is_inherited = strtobool(token);
+
 	token = pg_strtok(&length); /* eat :is_not_null */
 	token = pg_strtok(&length); /* get :is_not_null */
 	local_node->is_not_null = strtobool(token);

src/backend/tcop/utility.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.174 2002/08/29 00:17:04 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.175 2002/08/30 19:23:20 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -430,7 +430,8 @@ ProcessUtility(Node *parsetree,
 						renameatt(relid,
 								  stmt->oldname,	/* old att name */
 								  stmt->newname,	/* new att name */
-								  interpretInhOption(stmt->relation->inhOpt));	/* recursive? */
+								  interpretInhOption(stmt->relation->inhOpt),	/* recursive? */
+								  false);			/* recursing already? */
 						break;
 					case RENAME_TRIGGER:
 						renametrig(relid,
@@ -470,6 +471,7 @@ ProcessUtility(Node *parsetree,
 						 */
 						AlterTableAddColumn(relid,
 											interpretInhOption(stmt->relation->inhOpt),
+											false,
 											(ColumnDef *) stmt->def);
 						break;
 					case 'T':	/* ALTER COLUMN DEFAULT */
@@ -505,13 +507,13 @@ ProcessUtility(Node *parsetree,
 												   &(stmt->subtype));
 						break;
 					case 'D':	/* DROP COLUMN */
-						/*
-						 * XXX We don't actually recurse yet, but what we should do would be:
+						 /*
 						 * Recursively drop column from table and,
 						 * if requested, from descendants
 						 */
 						AlterTableDropColumn(relid,
 											 interpretInhOption(stmt->relation->inhOpt),
+											 false,
 											 stmt->name,
 											 stmt->behavior);
 						break;

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: catversion.h,v 1.154 2002/08/27 04:00:28 momjian Exp $
+ * $Id: catversion.h,v 1.155 2002/08/30 19:23:20 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200208271
+#define CATALOG_VERSION_NO	200208301
 
 #endif

src/include/catalog/pg_class.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_class.h,v 1.71 2002/08/15 16:36:07 momjian Exp $
+ * $Id: pg_class.h,v 1.72 2002/08/30 19:23:20 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -136,7 +136,7 @@ typedef FormData_pg_class *Form_pg_class;
 
 DATA(insert OID = 1247 (  pg_type		PGNSP 71 PGUID 0 1247 0 0 0 0 f f r 20 0 0 0 0 0 t f f f _null_ ));
 DESCR("");
-DATA(insert OID = 1249 (  pg_attribute	PGNSP 75 PGUID 0 1249 0 0 0 0 f f r 16 0 0 0 0 0 f f f f _null_ ));
+DATA(insert OID = 1249 (  pg_attribute	PGNSP 75 PGUID 0 1249 0 0 0 0 f f r 17 0 0 0 0 0 f f f f _null_ ));
 DESCR("");
 DATA(insert OID = 1255 (  pg_proc		PGNSP 81 PGUID 0 1255 0 0 0 0 f f r 15 0 0 0 0 0 t f f f _null_ ));
 DESCR("");

src/include/commands/tablecmds.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: tablecmds.h,v 1.5 2002/07/01 15:27:56 tgl Exp $
+ * $Id: tablecmds.h,v 1.6 2002/08/30 19:23:20 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,31 +16,31 @@
 
 #include "nodes/parsenodes.h"
 
-extern void AlterTableAddColumn(Oid myrelid, bool inherits,
+extern void AlterTableAddColumn(Oid myrelid, bool recurse, bool recursing,
 								ColumnDef *colDef);
 
-extern void AlterTableAlterColumnDefault(Oid myrelid, bool inh,
-										 const char *colName,
-										 Node *newDefault);
-
-extern void AlterTableAlterColumnDropNotNull(Oid myrelid, bool inh,
+extern void AlterTableAlterColumnDropNotNull(Oid myrelid, bool recurse,
 											 const char *colName);
 
-extern void AlterTableAlterColumnSetNotNull(Oid myrelid, bool inh,
+extern void AlterTableAlterColumnSetNotNull(Oid myrelid, bool recurse,
 											const char *colName);
 
-extern void AlterTableAlterColumnFlags(Oid myrelid, bool inh,
+extern void AlterTableAlterColumnDefault(Oid myrelid, bool recurse,
+										 const char *colName,
+										 Node *newDefault);
+
+extern void AlterTableAlterColumnFlags(Oid myrelid, bool recurse,
 									   const char *colName,
 									   Node *flagValue, const char *flagType);
 
-extern void AlterTableDropColumn(Oid myrelid, bool inh,
+extern void AlterTableDropColumn(Oid myrelid, bool recurse, bool recursing,
 					 			 const char *colName,
 								 DropBehavior behavior);
 
-extern void AlterTableAddConstraint(Oid myrelid, bool inh,
+extern void AlterTableAddConstraint(Oid myrelid, bool recurse,
 									List *newConstraints);
 
-extern void AlterTableDropConstraint(Oid myrelid, bool inh,
+extern void AlterTableDropConstraint(Oid myrelid, bool recurse,
 									 const char *constrName,
 									 DropBehavior behavior);
 
@@ -54,12 +54,13 @@ extern void RemoveRelation(const RangeVar *relation, DropBehavior behavior);
 
 extern void TruncateRelation(const RangeVar *relation);
 
-extern void renameatt(Oid relid,
+extern void renameatt(Oid myrelid,
 		  const char *oldattname,
 		  const char *newattname,
-		  bool recurse);
+		  bool recurse,
+		  bool recursing);
 
-extern void renamerel(Oid relid,
+extern void renamerel(Oid myrelid,
 		  const char *newrelname);
 
 #endif   /* TABLECMDS_H */

src/include/nodes/parsenodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.202 2002/08/27 04:55:12 tgl Exp $
+ * $Id: parsenodes.h,v 1.203 2002/08/30 19:23:20 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -279,6 +279,7 @@ typedef struct ColumnDef
 	NodeTag		type;
 	char	   *colname;		/* name of column */
 	TypeName   *typename;		/* type of column */
+	bool		is_inherited;	/* column is inherited? */
 	bool		is_not_null;	/* NOT NULL constraint specified? */
 	Node	   *raw_default;	/* default value (untransformed parse
 								 * tree) */

src/test/regress/expected/alter_table.out

@@ -1023,3 +1023,34 @@ select * from test;
 (3 rows)
 
 drop table test;
+-- test inheritance
+create table dropColumn (a int, b int, e int);
+create table dropColumnChild (c int) inherits (dropColumn);
+create table dropColumnAnother (d int) inherits (dropColumnChild);
+-- these two should fail
+alter table dropColumnchild drop column a;
+ERROR:  ALTER TABLE: Cannot drop inherited column "a"
+alter table only dropColumnChild drop column b;
+ERROR:  ALTER TABLE: Cannot drop inherited column "b"
+-- these three should work
+alter table only dropColumn drop column e;
+alter table dropColumnChild drop column c;
+alter table dropColumn drop column a;
+create table renameColumn (a int);
+create table renameColumnChild (b int) inherits (renameColumn);
+create table renameColumnAnother (c int) inherits (renameColumnChild);
+-- these three should fail
+alter table renameColumnChild rename column a to d;
+ERROR:  renameatt: inherited attribute "a" may not be renamed
+alter table only renameColumnChild rename column a to d;
+ERROR:  Inherited attribute "a" must be renamed in child tables too
+alter table only renameColumn rename column a to d;
+ERROR:  Inherited attribute "a" must be renamed in child tables too
+-- these should work
+alter table renameColumn rename column a to d;
+alter table renameColumnChild rename column b to a;
+-- this should work
+alter table renameColumn add column w int;
+-- this should fail
+alter table only renameColumn add column x int;
+ERROR:  Attribute must be added to child tables too

src/test/regress/sql/alter_table.sql

@@ -731,3 +731,36 @@ copy test(b,c) from stdin;
 select * from test;
 drop table test;
 
+-- test inheritance
+
+create table dropColumn (a int, b int, e int);
+create table dropColumnChild (c int) inherits (dropColumn);
+create table dropColumnAnother (d int) inherits (dropColumnChild);
+
+-- these two should fail
+alter table dropColumnchild drop column a;
+alter table only dropColumnChild drop column b;
+
+-- these three should work
+alter table only dropColumn drop column e;
+alter table dropColumnChild drop column c;
+alter table dropColumn drop column a;
+
+create table renameColumn (a int);
+create table renameColumnChild (b int) inherits (renameColumn);
+create table renameColumnAnother (c int) inherits (renameColumnChild);
+
+-- these three should fail
+alter table renameColumnChild rename column a to d;
+alter table only renameColumnChild rename column a to d;
+alter table only renameColumn rename column a to d;
+
+-- these should work
+alter table renameColumn rename column a to d;
+alter table renameColumnChild rename column b to a;
+
+-- this should work
+alter table renameColumn add column w int;
+
+-- this should fail
+alter table only renameColumn add column x int;