NAME
ALTER_FOREIGN_TABLE - change the definition of a foreign table
SYNOPSIS
ALTER FOREIGN TABLE [ IF EXISTS ] [ ONLY ] \nname\n [ * ]
\n
\naction\n [, ... ]
ALTER FOREIGN TABLE [ IF EXISTS ] [ ONLY ] \nname\n [ * ]
\n
RENAME [ COLUMN ] \ncolumn_name\n TO \nnew_column_name\n
ALTER FOREIGN TABLE [ IF EXISTS ] \nname\n
\n
RENAME TO \nnew_name\n
ALTER FOREIGN TABLE [ IF EXISTS ] \nname\n
\n
SET SCHEMA \nnew_schema\n
where \naction\n is one of:
\n
ADD [ COLUMN ] \ncolumn_name\n \ndata_type\n [ COLLATE \ncollation\n ] [ \ncolumn_constraint\n [ ... ] ]
\n
DROP [ COLUMN ] [ IF EXISTS ] \ncolumn_name\n [ RESTRICT | CASCADE ]
\n
ALTER [ COLUMN ] \ncolumn_name\n [ SET DATA ] TYPE \ndata_type\n [ COLLATE \ncollation\n ]
\n
ALTER [ COLUMN ] \ncolumn_name\n SET DEFAULT \nexpression\n
\n
ALTER [ COLUMN ] \ncolumn_name\n DROP DEFAULT
\n
ALTER [ COLUMN ] \ncolumn_name\n { SET | DROP } NOT NULL
\n
ALTER [ COLUMN ] \ncolumn_name\n SET STATISTICS \ninteger\n
\n
ALTER [ COLUMN ] \ncolumn_name\n SET ( \nattribute_option\n = \nvalue\n [, ... ] )
\n
ALTER [ COLUMN ] \ncolumn_name\n RESET ( \nattribute_option\n [, ... ] )
\n
ALTER [ COLUMN ] \ncolumn_name\n SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN | DEFAULT }
\n
ALTER [ COLUMN ] \ncolumn_name\n OPTIONS ( [ ADD | SET | DROP ] \noption\n ['\nvalue\n'] [, ... ])
\n
ADD \ntable_constraint\n [ NOT VALID ]
\n
VALIDATE CONSTRAINT \nconstraint_name\n
\n
DROP CONSTRAINT [ IF EXISTS ] \nconstraint_name\n [ RESTRICT | CASCADE ]
\n
DISABLE TRIGGER [ \ntrigger_name\n | ALL | USER ]
\n
ENABLE TRIGGER [ \ntrigger_name\n | ALL | USER ]
\n
ENABLE REPLICA TRIGGER \ntrigger_name\n
\n
ENABLE ALWAYS TRIGGER \ntrigger_name\n
\n
SET WITHOUT OIDS
\n
INHERIT \nparent_table\n
\n
NO INHERIT \nparent_table\n
\n
OWNER TO { \nnew_owner\n | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
\n
OPTIONS ( [ ADD | SET | DROP ] \noption\n ['\nvalue\n'] [, ... ])DESCRIPTION
ALTER FOREIGN TABLE changes the definition of an existing foreign table. There are several subforms:
ADD COLUMN
DROP COLUMN [ IF EXISTS ]
SET DATA TYPE
SET/DROP DEFAULT
SET/DROP NOT NULL
SET STATISTICS
SET ( attribute_option = value [, ... ] ) RESET ( attribute_option [, ... ] )
SET STORAGE
ADD table_constraint [ NOT VALID ]
Unlike the case when adding a constraint to a regular table, nothing is done to verify the constraint is correct; rather, this action simply declares that some new condition should be assumed to hold for all rows in the foreign table. (See the discussion in CREATE FOREIGN TABLE.) If the constraint is marked NOT VALID, then it isn't assumed to hold, but is only recorded for possible future use.
VALIDATE CONSTRAINT
DROP CONSTRAINT [ IF EXISTS ]
DISABLE/ENABLE [ REPLICA | ALWAYS ] TRIGGER
SET WITHOUT OIDS
INHERIT parent_table
NO INHERIT parent_table
OWNER
OPTIONS ( [ ADD | SET | DROP ] option ['value'] [, ... ] )
RENAME
SET SCHEMA
All the actions except RENAME and SET SCHEMA can be combined into a list of multiple alterations to apply in parallel. For example, it is possible to add several columns and/or alter the type of several columns in a single command.
If the command is written as ALTER FOREIGN TABLE IF EXISTS ... and the foreign table does not exist, no error is thrown. A notice is issued in this case.
You must own the table to use ALTER FOREIGN TABLE. To change the schema of a foreign table, you must also have CREATE privilege on the new schema. To alter the owner, you must be able to SET ROLE to the new owning role, and that role must have CREATE privilege on the table's schema. (These restrictions enforce that altering the owner doesn't do anything you couldn't do by dropping and recreating the table. However, a superuser can alter ownership of any table anyway.) To add a column or alter a column type, you must also have USAGE privilege on the data type.
PARAMETERS
name
column_name
new_column_name
new_name
data_type
table_constraint
constraint_name
CASCADE
RESTRICT
trigger_name
ALL
USER
parent_table
new_owner
new_schema
NOTES
The key word COLUMN is noise and can be omitted.
Consistency with the foreign server is not checked when a column is added or removed with ADD COLUMN or DROP COLUMN, a NOT NULL or CHECK constraint is added, or a column type is changed with SET DATA TYPE. It is the user's responsibility to ensure that the table definition matches the remote side.
Refer to CREATE FOREIGN TABLE for a further description of valid parameters.
EXAMPLES
To mark a column as not-null:
ALTER FOREIGN TABLE distributors ALTER COLUMN street SET NOT NULL;To change options of a foreign table:
ALTER FOREIGN TABLE myschema.distributors OPTIONS (ADD opt1 'value', SET opt2 'value2', DROP opt3);COMPATIBILITY
The forms ADD, DROP, and SET DATA TYPE conform with the SQL standard. The other forms are PostgreSQL extensions of the SQL standard. Also, the ability to specify more than one manipulation in a single ALTER FOREIGN TABLE command is an extension.
ALTER FOREIGN TABLE DROP COLUMN can be used to drop the only column of a foreign table, leaving a zero-column table. This is an extension of SQL, which disallows zero-column foreign tables.
SEE ALSO
CREATE FOREIGN TABLE (CREATE_FOREIGN_TABLE(7)), DROP FOREIGN TABLE (DROP_FOREIGN_TABLE(7))