Extended Syntax

Creating a table

column_constraint:

REFERENCES reftable

[ ( refcolumn ) ] [ MATCH

FULL | MATCH PARTIAL |

MATCH SIMPLE ][ ON

DELETE action ] [ ON

UPDATE action ]

Allows you to use REFERENCES reftable[ ( refcolumn ) ] [ MATCH FULL |MATCH PARTIAL | MATCH SIMPLE ] [ ON DELETE action ] [ ON UPDATE action ] to create foreign key constraints for tables.

Loading a module

CREATE EXTENSION

Loads a new module (such as DBLINK) to the current database.

DROP EXTENSION

Deletes the loaded module.

Aggregate functions

CREATE AGGREGATE

Defines a new aggregate function.

ALTER AGGREGATE

Modifies the definition of an aggregate function.

DROP AGGREGATE

Deletes an existing aggregate function.