pgsql-fix-inherit-rename.4.patch

*** a/src/backend/catalog/pg_inherits.c
--- b/src/backend/catalog/pg_inherits.c
***************
*** 28,33 ****
--- 28,34 ----
  #include "parser/parse_type.h"
  #include "storage/lmgr.h"
  #include "utils/fmgroids.h"
+ #include "utils/lsyscache.h"
  #include "utils/syscache.h"
  #include "utils/tqual.h"
  
***************
*** 190,195 **** find_all_inheritors(Oid parentrelId, LOCKMODE lockmode)
--- 191,257 ----
  	return rels_list;
  }
  
+ /*
+  * find_column_origin
+  *
+  * It returns a list of relation OIDs that defines the given column originally.
+  * In most cases, a certain column has one origin, unless it (or its parent)
+  * has multiple inheritance tree.
+  * Note that it returns a unique OID for diamond-type inheritance tree, because
+  * it shares same origin.
+  */
+ List *
+ find_column_origin(Oid relOid, const char *colName)
+ {
+ 	Relation	inhRel;
+ 	SysScanDesc	scan;
+ 	ScanKeyData	skey[1];
+ 	HeapTuple	tuple;
+ 	List	   *results = NIL;
+ 
+ 	/*
+ 	 * This relation does not contain the given column, is also means
+ 	 * the parent relation also.
+ 	 */
+ 	if (get_attnum(relOid, colName) == InvalidAttrNumber)
+ 		return NIL;
+ 
+ 	inhRel = heap_open(InheritsRelationId, AccessShareLock);
+ 
+ 	ScanKeyInit(&skey[0],
+ 				Anum_pg_inherits_inhrelid,
+ 				BTEqualStrategyNumber, F_OIDEQ,
+ 				ObjectIdGetDatum(relOid));
+ 
+ 	scan = systable_beginscan(inhRel, InheritsRelidSeqnoIndexId,
+ 							  true, SnapshotNow, 1, &skey);
+ 
+ 	while (HeapTupleIsValid(tuple = systable_getnext(scan)))
+ 	{
+ 		Form_pg_inherits	inhForm = (Form_pg_inherits) GETSTRUCT(tuple);
+ 		List	   *temp;
+ 
+ 		temp = find_column_origin(inhForm->inhparent, colName);
+ 		if (temp == NIL)
+ 			continue;
+ 
+ 		/*
+ 		 * Add to the queue only those children not already seen. This avoids
+ 		 * making duplicate entries in case of multiple inheritance paths from
+ 		 * the same parent.  (It'll also keep us from getting into an infinite
+ 		 * loop, though theoretically there can't be any cycles in the
+ 		 * inheritance graph anyway.)
+ 		 */
+ 		results = list_concat_unique_oid(results, temp);
+ 	}
+ 	systable_endscan(scan);
+ 	heap_close(inhRel, AccessShareLock);
+ 
+ 	if (results == NIL)
+ 		results = list_make1_oid(relOid);
+ 
+ 	return results;
+ }
  
  /*
   * has_subclass - does this relation have any children?
*** a/src/backend/commands/tablecmds.c
--- b/src/backend/commands/tablecmds.c
***************
*** 2009,2014 **** renameatt(Oid myrelid,
--- 2009,2025 ----
  				 errmsg("cannot rename inherited column \"%s\"",
  						oldattname)));
  
+ 	/*
+ 	 * if the attribute is multiple inherited, forbid the renaming,
+ 	 * even if we are already inside a recursive rename, because we
+ 	 * have no reasonable way to keep its integrity.
+ 	 */
+ 	if (list_length(find_column_origin(myrelid, oldattname)) > 1)
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+ 				 (errmsg("cannot rename multiple inherited column \"%s\"",
+ 						 oldattname))));
+ 
  	/* new name should not already exist */
  
  	/* this test is deliberately not attisdropped-aware */
***************
*** 5771,5776 **** ATPrepAlterColumnType(List **wqueue,
--- 5782,5788 ----
  					  bool recurse, bool recursing,
  					  AlterTableCmd *cmd)
  {
+ 	Oid			relOid = RelationGetRelid(rel);
  	char	   *colName = cmd->name;
  	TypeName   *typeName = (TypeName *) cmd->def;
  	HeapTuple	tuple;
***************
*** 5806,5811 **** ATPrepAlterColumnType(List **wqueue,
--- 5818,5830 ----
  				 errmsg("cannot alter inherited column \"%s\"",
  						colName)));
  
+ 	/* Don't alter multiple inherited columns */
+ 	if (list_length(find_column_origin(relOid, colName)) > 1)
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+ 				 (errmsg("cannot alter multiple inherited column \"%s\"",
+ 						 colName))));
+ 
  	/* Look up the target type */
  	targettype = typenameTypeId(NULL, typeName, &targettypmod);
  
*** a/src/include/catalog/pg_inherits_fn.h
--- b/src/include/catalog/pg_inherits_fn.h
***************
*** 19,24 ****
--- 19,25 ----
  
  extern List *find_inheritance_children(Oid parentrelId, LOCKMODE lockmode);
  extern List *find_all_inheritors(Oid parentrelId, LOCKMODE lockmode);
+ extern List *find_column_origin(Oid relOid, const char *colName);
  extern bool has_subclass(Oid relationId);
  extern bool typeInheritsFrom(Oid subclassTypeId, Oid superclassTypeId);
  
*** a/src/test/regress/expected/inherit.out
--- b/src/test/regress/expected/inherit.out
***************
*** 1053,1055 **** NOTICE:  merging column "a" with inherited definition
--- 1053,1133 ----
  ERROR:  column "a" has a storage parameter conflict
  DETAIL:  MAIN versus EXTENDED
  DROP TABLE t1, t2, t3, t4, t12_storage, t12_comments, t1_inh, t13_inh, t13_like, t_all;
+ -- Test for renaming and type changes (simple multiple inheritance)
+ CREATE TABLE t1 (a int, b int);
+ CREATE TABLE s1 (b int, c int);
+ CREATE TABLE ts (d int) INHERITS (t1, s1);
+ NOTICE:  merging multiple inherited definitions of column "b"
+ ALTER TABLE s1 ALTER b TYPE float;	-- to be failed
+ ERROR:  cannot alter multiple inherited column "b"
+ ALTER TABLE s1 ALTER c TYPE float;
+ ALTER TABLE ts ALTER c TYPE text;	-- to be failed
+ ERROR:  cannot alter inherited column "c"
+ ALTER TABLE ts ALTER d TYPE text;
+ ALTER TABLE t1 RENAME a TO aa;
+ ALTER TABLE t1 RENAME b TO bb;		-- to be failed
+ ERROR:  cannot rename multiple inherited column "b"
+ ALTER TABLE ts RENAME aa TO aaa;	-- to be failed
+ ERROR:  cannot rename inherited column "aa"
+ ALTER TABLE ts RENAME d TO dd;
+ \d+ ts
+                        Table "public.ts"
+  Column |       Type       | Modifiers | Storage  | Description 
+ --------+------------------+-----------+----------+-------------
+  aa     | integer          |           | plain    | 
+  b      | integer          |           | plain    | 
+  c      | double precision |           | plain    | 
+  dd     | text             |           | extended | 
+ Inherits: t1,
+           s1
+ Has OIDs: no
+ 
+ DROP TABLE ts;
+ -- Test for renaming and type changes (diamond inheritance)
+ CREATE TABLE t2 (x int) INHERITS (t1);
+ CREATE TABLE t3 (y int) INHERITS (t1);
+ CREATE TABLE t4 (z int) INHERITS (t2, t3);
+ NOTICE:  merging multiple inherited definitions of column "aa"
+ NOTICE:  merging multiple inherited definitions of column "b"
+ ALTER TABLE t1 ALTER aa TYPE float;
+ ALTER TABLE t1 RENAME aa TO aaa;
+ \d+ t4
+                        Table "public.t4"
+  Column |       Type       | Modifiers | Storage | Description 
+ --------+------------------+-----------+---------+-------------
+  aaa    | double precision |           | plain   | 
+  b      | integer          |           | plain   | 
+  x      | integer          |           | plain   | 
+  y      | integer          |           | plain   | 
+  z      | integer          |           | plain   | 
+ Inherits: t2,
+           t3
+ Has OIDs: no
+ 
+ CREATE TABLE ts (d int) INHERITS (t2, s1);
+ NOTICE:  merging multiple inherited definitions of column "b"
+ ALTER TABLE t1 ALTER aaa TYPE text;
+ ALTER TABLE t1 ALTER b TYPE text;	-- to be failed
+ ERROR:  cannot alter multiple inherited column "b"
+ ALTER TABLE t1 RENAME aaa TO aaaa;
+ ALTER TABLE t1 RENAME b TO bb;		-- to be failed
+ ERROR:  cannot rename multiple inherited column "b"
+ \d+ ts
+                        Table "public.ts"
+  Column |       Type       | Modifiers | Storage  | Description 
+ --------+------------------+-----------+----------+-------------
+  aaaa   | text             |           | extended | 
+  b      | integer          |           | plain    | 
+  x      | integer          |           | plain    | 
+  c      | double precision |           | plain    | 
+  d      | integer          |           | plain    | 
+ Inherits: t2,
+           s1
+ Has OIDs: no
+ 
+ DROP TABLE t1, s1 CASCADE;
+ NOTICE:  drop cascades to 4 other objects
+ DETAIL:  drop cascades to table t2
+ drop cascades to table ts
+ drop cascades to table t3
+ drop cascades to table t4
*** a/src/test/regress/sql/inherit.sql
--- b/src/test/regress/sql/inherit.sql
***************
*** 334,336 **** CREATE TABLE inh_error1 () INHERITS (t1, t4);
--- 334,372 ----
  CREATE TABLE inh_error2 (LIKE t4 INCLUDING STORAGE) INHERITS (t1);
  
  DROP TABLE t1, t2, t3, t4, t12_storage, t12_comments, t1_inh, t13_inh, t13_like, t_all;
+ 
+ -- Test for renaming and type changes (simple multiple inheritance)
+ CREATE TABLE t1 (a int, b int);
+ CREATE TABLE s1 (b int, c int);
+ CREATE TABLE ts (d int) INHERITS (t1, s1);
+ 
+ ALTER TABLE s1 ALTER b TYPE float;	-- to be failed
+ ALTER TABLE s1 ALTER c TYPE float;
+ ALTER TABLE ts ALTER c TYPE text;	-- to be failed
+ ALTER TABLE ts ALTER d TYPE text;
+ 
+ ALTER TABLE t1 RENAME a TO aa;
+ ALTER TABLE t1 RENAME b TO bb;		-- to be failed
+ ALTER TABLE ts RENAME aa TO aaa;	-- to be failed
+ ALTER TABLE ts RENAME d TO dd;
+ \d+ ts
+ 
+ DROP TABLE ts;
+ 
+ -- Test for renaming and type changes (diamond inheritance)
+ CREATE TABLE t2 (x int) INHERITS (t1);
+ CREATE TABLE t3 (y int) INHERITS (t1);
+ CREATE TABLE t4 (z int) INHERITS (t2, t3);
+ 
+ ALTER TABLE t1 ALTER aa TYPE float;
+ ALTER TABLE t1 RENAME aa TO aaa;
+ \d+ t4
+ 
+ CREATE TABLE ts (d int) INHERITS (t2, s1);
+ ALTER TABLE t1 ALTER aaa TYPE text;
+ ALTER TABLE t1 ALTER b TYPE text;	-- to be failed
+ ALTER TABLE t1 RENAME aaa TO aaaa;
+ ALTER TABLE t1 RENAME b TO bb;		-- to be failed
+ \d+ ts
+ 
+ DROP TABLE t1, s1 CASCADE;