This patch implement the TODO [ALTER DATABASE foo OWNER TO bar].

It was necessary to touch in grammar and create a new node to make home
to the new syntax. The command is also supported in E
CPG. Doc updates are attached too. Only superusers can change the owner
of the database. New owners don't need any aditional
privileges.

Euler Taveira de Oliveira

src/backend/commands/dbcommands.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.133 2004/05/26 04:41:10 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/dbcommands.c,v 1.134 2004/05/26 13:56:45 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -776,6 +776,52 @@ AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
 }
 
 
+/*
+ * ALTER DATABASE name OWNER TO newowner
+ */
+void
+AlterDatabaseOwner(const char *dbname, const char *newowner)
+{
+	AclId		newdatdba;
+	HeapTuple	tuple,
+				newtuple;
+	Relation	rel;
+	ScanKeyData scankey;
+	SysScanDesc scan;
+
+	rel = heap_openr(DatabaseRelationName, RowExclusiveLock);
+	ScanKeyInit(&scankey,
+				Anum_pg_database_datname,
+				BTEqualStrategyNumber, F_NAMEEQ,
+				NameGetDatum(dbname));
+	scan = systable_beginscan(rel, DatabaseNameIndex, true,
+							  SnapshotNow, 1, &scankey);
+	tuple = systable_getnext(scan);
+	if (!HeapTupleIsValid(tuple))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_DATABASE),
+				 errmsg("database \"%s\" does not exist", dbname)));
+
+	/* obtain sysid of proposed owner */
+	newdatdba = get_usesysid(newowner); /* will ereport if no such user */
+
+	/* changing owner's database for someone else: must be superuser */
+	/* note that the someone else need not have any permissions */
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("must be superuser to change owner's database for another user")));
+
+	/* change owner */
+	newtuple = heap_copytuple(tuple);
+	((Form_pg_database) GETSTRUCT(newtuple))->datdba = newdatdba;
+	simple_heap_update(rel, &tuple->t_self, newtuple);
+	CatalogUpdateIndexes(rel, newtuple);
+
+	systable_endscan(scan);
+	heap_close(rel, NoLock);
+}
+
 
 /*
  * Helper functions

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.282 2004/05/26 04:41:18 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.283 2004/05/26 13:56:47 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2068,6 +2068,17 @@ _copyCreatedbStmt(CreatedbStmt *from)
 	return newnode;
 }
 
+static AlterDbOwnerStmt *
+_copyAlterDbOwnerStmt(AlterDbOwnerStmt *from)
+{
+	AlterDbOwnerStmt *newnode = makeNode(AlterDbOwnerStmt);
+
+	COPY_STRING_FIELD(dbname);
+	COPY_STRING_FIELD(uname);
+
+	return newnode;
+}
+
 static AlterDatabaseSetStmt *
 _copyAlterDatabaseSetStmt(AlterDatabaseSetStmt *from)
 {
@@ -2860,6 +2871,9 @@ copyObject(void *from)
 		case T_CreatedbStmt:
 			retval = _copyCreatedbStmt(from);
 			break;
+		case T_AlterDbOwnerStmt:
+			retval = _copyAlterDbOwnerStmt(from);
+			break;
 		case T_AlterDatabaseSetStmt:
 			retval = _copyAlterDatabaseSetStmt(from);
 			break;

src/backend/nodes/equalfuncs.c

@@ -18,7 +18,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.221 2004/05/26 04:41:19 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.222 2004/05/26 13:56:47 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1099,6 +1099,15 @@ _equalCreatedbStmt(CreatedbStmt *a, CreatedbStmt *b)
 	return true;
 }
 
+static bool
+_equalAlterDbOwnerStmt(AlterDbOwnerStmt *a, AlterDbOwnerStmt *b)
+{
+	COMPARE_STRING_FIELD(dbname);
+	COMPARE_STRING_FIELD(uname);
+
+	return true;
+}
+
 static bool
 _equalAlterDatabaseSetStmt(AlterDatabaseSetStmt *a, AlterDatabaseSetStmt *b)
 {
@@ -2005,6 +2014,9 @@ equal(void *a, void *b)
 		case T_CreatedbStmt:
 			retval = _equalCreatedbStmt(a, b);
 			break;
+		case T_AlterDbOwnerStmt:
+			retval = _equalAlterDbOwnerStmt(a, b);
+			break;
 		case T_AlterDatabaseSetStmt:
 			retval = _equalAlterDatabaseSetStmt(a, b);
 			break;

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.455 2004/05/26 04:41:29 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.456 2004/05/26 13:56:51 momjian Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -152,6 +152,7 @@ static void doNegateFloat(Value *v);
 		VariableResetStmt VariableSetStmt VariableShowStmt
 		ViewStmt CheckPointStmt CreateConversionStmt
 		DeallocateStmt PrepareStmt ExecuteStmt
+		AlterDbOwnerStmt
 
 %type <node>	select_no_parens select_with_parens select_clause
 				simple_select
@@ -486,7 +487,8 @@ stmtmulti:	stmtmulti ';' stmt
 		;
 
 stmt :
-			AlterDatabaseSetStmt
+			AlterDbOwnerStmt
+			| AlterDatabaseSetStmt
 			| AlterDomainStmt
 			| AlterGroupStmt
 			| AlterSeqStmt
@@ -3918,6 +3920,15 @@ opt_equal:	'='										{}
  *
  *****************************************************************************/
 
+AlterDbOwnerStmt: ALTER DATABASE database_name OWNER TO UserId
+				{
+					AlterDbOwnerStmt *n = makeNode(AlterDbOwnerStmt);
+					n->dbname = $3;
+					n->uname = $6;
+					$$ = (Node *)n;
+				}
+		;
+
 AlterDatabaseSetStmt:
 			ALTER DATABASE database_name SET set_rest
 				{

src/backend/tcop/utility.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.216 2004/05/26 04:41:35 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.217 2004/05/26 13:56:54 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -234,6 +234,7 @@ check_xact_readonly(Node *parsetree)
 	switch (nodeTag(parsetree))
 	{
 		case T_AlterDatabaseSetStmt:
+		case T_AlterDbOwnerStmt:
 		case T_AlterDomainStmt:
 		case T_AlterGroupStmt:
 		case T_AlterSeqStmt:
@@ -675,6 +676,13 @@ ProcessUtility(Node *parsetree,
 			createdb((CreatedbStmt *) parsetree);
 			break;
 
+		case T_AlterDbOwnerStmt:
+			{
+				AlterDbOwnerStmt *stmt = (AlterDbOwnerStmt *) parsetree;
+				AlterDatabaseOwner(stmt->dbname, stmt->uname);
+			}
+			break;
+
 		case T_AlterDatabaseSetStmt:
 			AlterDatabaseSet((AlterDatabaseSetStmt *) parsetree);
 			break;
@@ -1303,6 +1311,10 @@ CreateCommandTag(Node *parsetree)
 			tag = "CREATE DATABASE";
 			break;
 
+		case T_AlterDbOwnerStmt:
+			tag = "ALTER DATABASE";
+			break;
+
 		case T_AlterDatabaseSetStmt:
 			tag = "ALTER DATABASE";
 			break;