ALTER TABLE rewrite. New cool stuff:

* ALTER ... ADD COLUMN with defaults and NOT NULL constraints works per SQL
spec.  A default is implemented by rewriting the table with the new value
stored in each row.

* ALTER COLUMN TYPE.  You can change a column's datatype to anything you
want, so long as you can specify how to convert the old value.  Rewrites
the table.  (Possible future improvement: optimize no-op conversions such
as varchar(N) to varchar(N+1).)

* Multiple ALTER actions in a single ALTER TABLE command.  You can perform
any number of column additions, type changes, and constraint additions with
only one pass over the table contents.

Basic documentation provided in ALTER TABLE ref page, but some more docs
work is needed.

Original patch from Rod Taylor, additional work from Tom Lane.

1 files changed, 8 insertions, 123 deletions

diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 98c63fd0e64..68e9f846725 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 1.213 2004/04/22 02:58:20 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.214 2004/05/05 04:48:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -43,7 +43,6 @@
 #include "commands/view.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
-#include "parser/parse_clause.h"
 #include "parser/parse_expr.h"
 #include "parser/parse_type.h"
 #include "rewrite/rewriteDefine.h"
@@ -497,126 +496,8 @@ ProcessUtility(Node *parsetree,
 			ExecRenameStmt((RenameStmt *) parsetree);
 			break;
 
-			/* various Alter Table forms */
-
 		case T_AlterTableStmt:
-			{
-				AlterTableStmt *stmt = (AlterTableStmt *) parsetree;
-				Oid			relid;
-
-				relid = RangeVarGetRelid(stmt->relation, false);
-
-				/*
-				 * Some or all of these functions are recursive to cover
-				 * inherited things, so permission checks are done there.
-				 */
-				switch (stmt->subtype)
-				{
-					case 'A':	/* ADD COLUMN */
-
-						/*
-						 * Recursively add column to table and, if
-						 * requested, to descendants
-						 */
-						AlterTableAddColumn(relid,
-							  interpretInhOption(stmt->relation->inhOpt),
-											(ColumnDef *) stmt->def);
-						break;
-					case 'T':	/* ALTER COLUMN DEFAULT */
-
-						/*
-						 * Recursively alter column default for table and,
-						 * if requested, for descendants
-						 */
-						AlterTableAlterColumnDefault(relid,
-							  interpretInhOption(stmt->relation->inhOpt),
-													 stmt->name,
-													 stmt->def);
-						break;
-					case 'N':	/* ALTER COLUMN DROP NOT NULL */
-						AlterTableAlterColumnDropNotNull(relid,
-							  interpretInhOption(stmt->relation->inhOpt),
-														 stmt->name);
-						break;
-					case 'n':	/* ALTER COLUMN SET NOT NULL */
-						AlterTableAlterColumnSetNotNull(relid,
-							  interpretInhOption(stmt->relation->inhOpt),
-														stmt->name);
-						break;
-					case 'S':	/* ALTER COLUMN STATISTICS */
-					case 'M':	/* ALTER COLUMN STORAGE */
-
-						/*
-						 * Recursively alter column statistics for table
-						 * and, if requested, for descendants
-						 */
-						AlterTableAlterColumnFlags(relid,
-							  interpretInhOption(stmt->relation->inhOpt),
-												   stmt->name,
-												   stmt->def,
-												   &(stmt->subtype));
-						break;
-					case 'D':	/* DROP COLUMN */
-
-						/*
-						 * Recursively drop column from table and, if
-						 * requested, from descendants
-						 */
-						AlterTableDropColumn(relid,
-							  interpretInhOption(stmt->relation->inhOpt),
-											 false,
-											 stmt->name,
-											 stmt->behavior);
-						break;
-					case 'C':	/* ADD CONSTRAINT */
-
-						/*
-						 * Recursively add constraint to table and, if
-						 * requested, to descendants
-						 */
-						AlterTableAddConstraint(relid,
-							  interpretInhOption(stmt->relation->inhOpt),
-												(List *) stmt->def);
-						break;
-					case 'X':	/* DROP CONSTRAINT */
-
-						/*
-						 * Recursively drop constraint from table and, if
-						 * requested, from descendants
-						 */
-						AlterTableDropConstraint(relid,
-							  interpretInhOption(stmt->relation->inhOpt),
-												 stmt->name,
-												 stmt->behavior);
-						break;
-					case 'E':	/* CREATE TOAST TABLE */
-						AlterTableCreateToastTable(relid, false);
-						break;
-					case 'U':	/* ALTER OWNER */
-						/* check that we are the superuser */
-						if (!superuser())
-							ereport(ERROR,
-								(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
-							errmsg("must be superuser to alter owner")));
-						/* get_usesysid raises an error if no such user */
-						AlterTableOwner(relid,
-										get_usesysid(stmt->name));
-						break;
-					case 'L':	/* CLUSTER ON */
-						AlterTableClusterOn(relid, stmt->name);
-						break;
-					case 'o':	/* SET WITHOUT OIDS */
-						AlterTableAlterOids(relid,
-											false,
-							  interpretInhOption(stmt->relation->inhOpt),
-											DROP_RESTRICT);
-						break;
-					default:	/* oops */
-						elog(ERROR, "unrecognized alter table type: %d",
-							 (int) stmt->subtype);
-						break;
-				}
-			}
+			AlterTable((AlterTableStmt *) parsetree);
 			break;
 
 		case T_AlterDomainStmt:
@@ -736,11 +617,15 @@ ProcessUtility(Node *parsetree,
 							stmt->idxname,		/* index name */
 							stmt->accessMethod, /* am name */
 							stmt->indexParams,	/* parameters */
+							(Expr *) stmt->whereClause,
+							stmt->rangetable,
 							stmt->unique,
 							stmt->primary,
 							stmt->isconstraint,
-							(Expr *) stmt->whereClause,
-							stmt->rangetable);
+							false,				/* is_alter_table */
+							true,				/* check_rights */
+							false,				/* skip_build */
+							false);				/* quiet */
 			}
 			break;