ALTER FOREIGN TABLE(7) PostgreSQL 9.1.9 Documentation ALTER FOREIGN TABLE(7)NAMEALTER_FOREIGN_TABLE - change the definition of a foreign table
SYNOPSIS
ALTER FOREIGN TABLE name
action [, ... ]
ALTER FOREIGN TABLE name
RENAME [ COLUMN ] column TO new_column
ALTER FOREIGN TABLE name
RENAME TO new_name
ALTER FOREIGN TABLE name
SET SCHEMA new_schema
where action is one of:
ADD [ COLUMN ] column type [ NULL | NOT NULL ]
DROP [ COLUMN ] [ IF EXISTS ] column [ RESTRICT | CASCADE ]
ALTER [ COLUMN ] column [ SET DATA ] TYPE type
ALTER [ COLUMN ] column { SET | DROP } NOT NULL
OWNER TO new_owner
OPTIONS ( [ ADD | SET | DROP ] option ['value'] [, ... ])
DESCRIPTION
ALTER FOREIGN TABLE changes the definition of an existing foreign
table. There are several subforms:
ADD COLUMN
This form adds a new column to the foreign table, using the same
syntax as CREATE FOREIGN TABLE (CREATE_FOREIGN_TABLE(7)).
DROP COLUMN [ IF EXISTS ]
This form drops a column from a foreign table. You will need to say
CASCADE if anything outside the table depends on the column; for
example, views. If IF EXISTS is specified and the column does not
exist, no error is thrown. In this case a notice is issued instead.
SET DATA TYPE
This form changes the type of a column of a foreign table.
SET/DROP NOT NULL
Mark a column as allowing, or not allowing, null values.
OWNER
This form changes the owner of the foreign table to the specified
user.
RENAME
The RENAME forms change the name of a foreign table or the name of
an individual column in a foreign table.
SET SCHEMA
This form moves the foreign table into another schema.
OPTIONS ( [ ADD | SET | DROP ] option ['value'] [, ... ] )
Change options for the foreign table. ADD, SET, and DROP specify
the action to be performed. ADD is assumed if no operation is
explicitly specified. Option names must be unique; names and values
are also validated using the foreign data wrapper library.
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.
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 also be a direct or indirect
member of 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.)
PARAMETERS
name
The name (possibly schema-qualified) of an existing foreign table
to alter.
column
Name of a new or existing column.
new_column
New name for an existing column.
new_name
New name for the table.
type
Data type of the new column, or new data type for an existing
column.
CASCADE
Automatically drop objects that depend on the dropped column (for
example, views referencing the column).
RESTRICT
Refuse to drop the column if there are any dependent objects. This
is the default behavior.
new_owner
The user name of the new owner of the table.
new_schema
The name of the schema to which the table will be moved.
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 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 (CREATE_FOREIGN_TABLE(7)) 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 'value3');
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.
PostgreSQL 9.1.9 2013-04-01 ALTER FOREIGN TABLE(7)