Sophie: postgresql9.6-docs-9.6.4-1.mga6 noarch

postgresql9.6-docs-9.6.4-1.mga6.noarch.rpm

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>ALTER FOREIGN TABLE</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REV="MADE"
HREF="mailto:pgsql-docs@postgresql.org"><LINK
REL="HOME"
TITLE="PostgreSQL 9.6.4 Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="SQL Commands"
HREF="sql-commands.html"><LINK
REL="PREVIOUS"
TITLE="ALTER FOREIGN DATA WRAPPER"
HREF="sql-alterforeigndatawrapper.html"><LINK
REL="NEXT"
TITLE="ALTER FUNCTION"
HREF="sql-alterfunction.html"><LINK
REL="STYLESHEET"
TYPE="text/css"
HREF="stylesheet.css"><META
HTTP-EQUIV="Content-Type"
CONTENT="text/html; charset=ISO-8859-1"><META
NAME="creation"
CONTENT="2017-08-11T02:27:18"></HEAD
><BODY
CLASS="REFENTRY"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="4"
ALIGN="center"
VALIGN="bottom"
><A
HREF="index.html"
>PostgreSQL 9.6.4 Documentation</A
></TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
TITLE="ALTER FOREIGN DATA WRAPPER"
HREF="sql-alterforeigndatawrapper.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="top"
><A
HREF="sql-commands.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="60%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="20%"
ALIGN="right"
VALIGN="top"
><A
TITLE="ALTER FUNCTION"
HREF="sql-alterfunction.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="SQL-ALTERFOREIGNTABLE"
></A
>ALTER FOREIGN TABLE</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN73254"
></A
><H2
>Name</H2
>ALTER FOREIGN TABLE&nbsp;--&nbsp;change the definition of a foreign table</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN73257"
></A
><H2
>Synopsis</H2
><PRE
CLASS="SYNOPSIS"
>ALTER FOREIGN TABLE [ IF EXISTS ] [ ONLY ] <TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
> [ * ]
    <TT
CLASS="REPLACEABLE"
><I
>action</I
></TT
> [, ... ]
ALTER FOREIGN TABLE [ IF EXISTS ] [ ONLY ] <TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
> [ * ]
    RENAME [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> TO <TT
CLASS="REPLACEABLE"
><I
>new_column_name</I
></TT
>
ALTER FOREIGN TABLE [ IF EXISTS ] <TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
>
    RENAME TO <TT
CLASS="REPLACEABLE"
><I
>new_name</I
></TT
>
ALTER FOREIGN TABLE [ IF EXISTS ] <TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
>
    SET SCHEMA <TT
CLASS="REPLACEABLE"
><I
>new_schema</I
></TT
>

<SPAN
CLASS="phrase"
><SPAN
CLASS="PHRASE"
>where <TT
CLASS="REPLACEABLE"
><I
>action</I
></TT
> is one of:</SPAN
></SPAN
>

    ADD [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> <TT
CLASS="REPLACEABLE"
><I
>data_type</I
></TT
> [ COLLATE <TT
CLASS="REPLACEABLE"
><I
>collation</I
></TT
> ] [ <TT
CLASS="REPLACEABLE"
><I
>column_constraint</I
></TT
> [ ... ] ]
    DROP [ COLUMN ] [ IF EXISTS ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> [ RESTRICT | CASCADE ]
    ALTER [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> [ SET DATA ] TYPE <TT
CLASS="REPLACEABLE"
><I
>data_type</I
></TT
> [ COLLATE <TT
CLASS="REPLACEABLE"
><I
>collation</I
></TT
> ]
    ALTER [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> SET DEFAULT <TT
CLASS="REPLACEABLE"
><I
>expression</I
></TT
>
    ALTER [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> DROP DEFAULT
    ALTER [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> { SET | DROP } NOT NULL
    ALTER [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> SET STATISTICS <TT
CLASS="REPLACEABLE"
><I
>integer</I
></TT
>
    ALTER [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> SET ( <TT
CLASS="REPLACEABLE"
><I
>attribute_option</I
></TT
> = <TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
> [, ... ] )
    ALTER [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> RESET ( <TT
CLASS="REPLACEABLE"
><I
>attribute_option</I
></TT
> [, ... ] )
    ALTER [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> SET STORAGE { PLAIN | EXTERNAL | EXTENDED | MAIN }
    ALTER [ COLUMN ] <TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
> OPTIONS ( [ ADD | SET | DROP ] <TT
CLASS="REPLACEABLE"
><I
>option</I
></TT
> ['<TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
>'] [, ... ])
    ADD <TT
CLASS="REPLACEABLE"
><I
>table_constraint</I
></TT
> [ NOT VALID ]
    VALIDATE CONSTRAINT <TT
CLASS="REPLACEABLE"
><I
>constraint_name</I
></TT
>
    DROP CONSTRAINT [ IF EXISTS ]  <TT
CLASS="REPLACEABLE"
><I
>constraint_name</I
></TT
> [ RESTRICT | CASCADE ]
    DISABLE TRIGGER [ <TT
CLASS="REPLACEABLE"
><I
>trigger_name</I
></TT
> | ALL | USER ]
    ENABLE TRIGGER [ <TT
CLASS="REPLACEABLE"
><I
>trigger_name</I
></TT
> | ALL | USER ]
    ENABLE REPLICA TRIGGER <TT
CLASS="REPLACEABLE"
><I
>trigger_name</I
></TT
>
    ENABLE ALWAYS TRIGGER <TT
CLASS="REPLACEABLE"
><I
>trigger_name</I
></TT
>
    SET WITH OIDS
    SET WITHOUT OIDS
    INHERIT <TT
CLASS="REPLACEABLE"
><I
>parent_table</I
></TT
>
    NO INHERIT <TT
CLASS="REPLACEABLE"
><I
>parent_table</I
></TT
>
    OWNER TO { <TT
CLASS="REPLACEABLE"
><I
>new_owner</I
></TT
> | CURRENT_USER | SESSION_USER }
    OPTIONS ( [ ADD | SET | DROP ] <TT
CLASS="REPLACEABLE"
><I
>option</I
></TT
> ['<TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
>'] [, ... ])</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73305"
></A
><H2
>Description</H2
><P
>   <TT
CLASS="COMMAND"
>ALTER FOREIGN TABLE</TT
> changes the definition of an
   existing foreign table.  There are several subforms:

  <P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>ADD COLUMN</TT
></DT
><DD
><P
>      This form adds a new column to the foreign table, using the same syntax as
      <A
HREF="sql-createforeigntable.html"
>CREATE FOREIGN TABLE</A
>.
      Unlike the case when adding a column to a regular table, nothing happens
      to the underlying storage: this action simply declares that
      some new column is now accessible through the foreign table.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>DROP COLUMN [ IF EXISTS ]</TT
></DT
><DD
><P
>      This form drops a column from a foreign table.
      You will need to say <TT
CLASS="LITERAL"
>CASCADE</TT
> if
      anything outside the table depends on the column; for example,
      views.
      If <TT
CLASS="LITERAL"
>IF EXISTS</TT
> is specified and the column
      does not exist, no error is thrown. In this case a notice
      is issued instead.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>SET DATA TYPE</TT
></DT
><DD
><P
>      This form changes the type of a column of a foreign table.
      Again, this has no effect on any underlying storage: this action simply
      changes the type that <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> believes the column to
      have.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>SET</TT
>/<TT
CLASS="LITERAL"
>DROP DEFAULT</TT
></DT
><DD
><P
>      These forms set or remove the default value for a column.
      Default values only apply in subsequent <TT
CLASS="COMMAND"
>INSERT</TT
>
      or <TT
CLASS="COMMAND"
>UPDATE</TT
> commands; they do not cause rows already in the
      table to change.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>SET</TT
>/<TT
CLASS="LITERAL"
>DROP NOT NULL</TT
></DT
><DD
><P
>      Mark a column as allowing, or not allowing, null values.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>SET STATISTICS</TT
></DT
><DD
><P
>      This form
      sets the per-column statistics-gathering target for subsequent
      <A
HREF="sql-analyze.html"
>ANALYZE</A
> operations.
      See the similar form of <A
HREF="sql-altertable.html"
>ALTER TABLE</A
>
      for more details.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>SET ( <TT
CLASS="REPLACEABLE"
><I
>attribute_option</I
></TT
> = <TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
> [, ... ] )</TT
><BR><TT
CLASS="LITERAL"
>RESET ( <TT
CLASS="REPLACEABLE"
><I
>attribute_option</I
></TT
> [, ... ] )</TT
></DT
><DD
><P
>      This form sets or resets per-attribute options.
      See the similar form of <A
HREF="sql-altertable.html"
>ALTER TABLE</A
>
      for more details.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>SET STORAGE</TT
></DT
><DD
><P
>      This form sets the storage mode for a column.
      See the similar form of <A
HREF="sql-altertable.html"
>ALTER TABLE</A
>
      for more details.
      Note that the storage mode has no effect unless the table's
      foreign-data wrapper chooses to pay attention to it.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>ADD <TT
CLASS="REPLACEABLE"
><I
>table_constraint</I
></TT
> [ NOT VALID ]</TT
></DT
><DD
><P
>      This form adds a new constraint to a foreign table, using the same
      syntax as <A
HREF="sql-createforeigntable.html"
>CREATE FOREIGN TABLE</A
>.
      Currently only <TT
CLASS="LITERAL"
>CHECK</TT
> constraints are supported.
     </P
><P
>      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 <A
HREF="sql-createforeigntable.html"
>CREATE FOREIGN TABLE</A
>.)
      If the constraint is marked <TT
CLASS="LITERAL"
>NOT VALID</TT
>, then it isn't
      assumed to hold, but is only recorded for possible future use.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>VALIDATE CONSTRAINT</TT
></DT
><DD
><P
>      This form marks as valid a constraint that was previously marked
      as <TT
CLASS="LITERAL"
>NOT VALID</TT
>.  No action is taken to verify the
      constraint, but future queries will assume that it holds.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>DROP CONSTRAINT [ IF EXISTS ]</TT
></DT
><DD
><P
>      This form drops the specified constraint on a foreign table.
      If <TT
CLASS="LITERAL"
>IF EXISTS</TT
> is specified and the constraint
      does not exist, no error is thrown.
      In this case a notice is issued instead.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>DISABLE</TT
>/<TT
CLASS="LITERAL"
>ENABLE [ REPLICA | ALWAYS ] TRIGGER</TT
></DT
><DD
><P
>      These forms configure the firing of trigger(s) belonging to the foreign
      table.  See the similar form of <A
HREF="sql-altertable.html"
>ALTER TABLE</A
> for more
      details.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>SET WITH OIDS</TT
></DT
><DD
><P
>      This form adds an <TT
CLASS="LITERAL"
>oid</TT
> system column to the
      table (see <A
HREF="ddl-system-columns.html"
>Section 5.4</A
>).
      It does nothing if the table already has OIDs.
      Unless the table's foreign-data wrapper supports OIDs, this column
      will simply read as zeroes.
     </P
><P
>      Note that this is not equivalent to <TT
CLASS="LITERAL"
>ADD COLUMN oid oid</TT
>;
      that would add a normal column that happened to be named
      <TT
CLASS="LITERAL"
>oid</TT
>, not a system column.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>SET WITHOUT OIDS</TT
></DT
><DD
><P
>      This form removes the <TT
CLASS="LITERAL"
>oid</TT
> system column from the
      table.  This is exactly equivalent to
      <TT
CLASS="LITERAL"
>DROP COLUMN oid RESTRICT</TT
>,
      except that it will not complain if there is already no
      <TT
CLASS="LITERAL"
>oid</TT
> column.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>INHERIT <TT
CLASS="REPLACEABLE"
><I
>parent_table</I
></TT
></TT
></DT
><DD
><P
>      This form adds the target foreign table as a new child of the specified
      parent table.
      See the similar form of <A
HREF="sql-altertable.html"
>ALTER TABLE</A
>
      for more details.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>NO INHERIT <TT
CLASS="REPLACEABLE"
><I
>parent_table</I
></TT
></TT
></DT
><DD
><P
>      This form removes the target foreign table from the list of children of
      the specified parent table.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>OWNER</TT
></DT
><DD
><P
>      This form changes the owner of the foreign table to the
      specified user.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>OPTIONS ( [ ADD | SET | DROP ] <TT
CLASS="REPLACEABLE"
><I
>option</I
></TT
> ['<TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
>'] [, ... ] )</TT
></DT
><DD
><P
>      Change options for the foreign table or one of its columns.
      <TT
CLASS="LITERAL"
>ADD</TT
>, <TT
CLASS="LITERAL"
>SET</TT
>, and <TT
CLASS="LITERAL"
>DROP</TT
>
      specify the action to be performed.  <TT
CLASS="LITERAL"
>ADD</TT
> is assumed
      if no operation is explicitly specified.  Duplicate option names are not
      allowed (although it's OK for a table option and a column option to have
      the same name).  Option names and values are also validated using the
      foreign data wrapper library.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>RENAME</TT
></DT
><DD
><P
>      The <TT
CLASS="LITERAL"
>RENAME</TT
> forms change the name of a foreign table
      or the name of an individual column in a foreign table.
     </P
></DD
><DT
><TT
CLASS="LITERAL"
>SET SCHEMA</TT
></DT
><DD
><P
>      This form moves the foreign table into another schema.
     </P
></DD
></DL
></DIV
><P>
  </P
><P
>   All the actions except <TT
CLASS="LITERAL"
>RENAME</TT
> and <TT
CLASS="LITERAL"
>SET SCHEMA</TT
>
   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.
  </P
><P
>   If the command is written as <TT
CLASS="LITERAL"
>ALTER FOREIGN TABLE IF EXISTS ...</TT
>
   and the foreign table does not exist, no error is thrown. A notice is
   issued in this case.
  </P
><P
>   You must own the table to use <TT
CLASS="COMMAND"
>ALTER FOREIGN TABLE</TT
>.
   To change the schema of a foreign table, you must also have
   <TT
CLASS="LITERAL"
>CREATE</TT
> 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 <TT
CLASS="LITERAL"
>CREATE</TT
> 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 <TT
CLASS="LITERAL"
>USAGE</TT
> privilege on the data type.
  </P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73465"
></A
><H2
>Parameters</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
></DT
><DD
><P
>        The name (possibly schema-qualified) of an existing foreign table to
        alter. If <TT
CLASS="LITERAL"
>ONLY</TT
> is specified before the table name, only
        that table is altered. If <TT
CLASS="LITERAL"
>ONLY</TT
> is not specified, the table
        and all its descendant tables (if any) are altered.  Optionally,
        <TT
CLASS="LITERAL"
>*</TT
> can be specified after the table name to explicitly
        indicate that descendant tables are included.
       </P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>column_name</I
></TT
></DT
><DD
><P
>        Name of a new or existing column.
       </P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>new_column_name</I
></TT
></DT
><DD
><P
>        New name for an existing column.
       </P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>new_name</I
></TT
></DT
><DD
><P
>        New name for the table.
       </P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>data_type</I
></TT
></DT
><DD
><P
>        Data type of the new column, or new data type for an existing
        column.
       </P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>table_constraint</I
></TT
></DT
><DD
><P
>        New table constraint for the foreign table.
       </P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>constraint_name</I
></TT
></DT
><DD
><P
>        Name of an existing constraint to drop.
       </P
></DD
><DT
><TT
CLASS="LITERAL"
>CASCADE</TT
></DT
><DD
><P
>        Automatically drop objects that depend on the dropped column
        or constraint (for example, views referencing the column),
        and in turn all objects that depend on those objects
        (see <A
HREF="ddl-depend.html"
>Section 5.13</A
>).
       </P
></DD
><DT
><TT
CLASS="LITERAL"
>RESTRICT</TT
></DT
><DD
><P
>        Refuse to drop the column or constraint if there are any dependent
        objects. This is the default behavior.
       </P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>trigger_name</I
></TT
></DT
><DD
><P
>        Name of a single trigger to disable or enable.
       </P
></DD
><DT
><TT
CLASS="LITERAL"
>ALL</TT
></DT
><DD
><P
>        Disable or enable all triggers belonging to the foreign table.  (This
        requires superuser privilege if any of the triggers are internally
        generated triggers.  The core system does not add such triggers to
        foreign tables, but add-on code could do so.)
       </P
></DD
><DT
><TT
CLASS="LITERAL"
>USER</TT
></DT
><DD
><P
>        Disable or enable all triggers belonging to the foreign table except
        for internally generated triggers.
       </P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>parent_table</I
></TT
></DT
><DD
><P
>        A parent table to associate or de-associate with this foreign table.
       </P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>new_owner</I
></TT
></DT
><DD
><P
>        The user name of the new owner of the table.
       </P
></DD
><DT
><TT
CLASS="REPLACEABLE"
><I
>new_schema</I
></TT
></DT
><DD
><P
>        The name of the schema to which the table will be moved.
       </P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73547"
></A
><H2
>Notes</H2
><P
>    The key word <TT
CLASS="LITERAL"
>COLUMN</TT
> is noise and can be omitted.
   </P
><P
>    Consistency with the foreign server is not checked when a column is added
    or removed with <TT
CLASS="LITERAL"
>ADD COLUMN</TT
> or
    <TT
CLASS="LITERAL"
>DROP COLUMN</TT
>, a <TT
CLASS="LITERAL"
>NOT NULL</TT
>
    or <TT
CLASS="LITERAL"
>CHECK</TT
> constraint is added, or a column type is changed
    with <TT
CLASS="LITERAL"
>SET DATA TYPE</TT
>.  It is the user's responsibility to ensure
    that the table definition matches the remote side.
   </P
><P
>    Refer to <A
HREF="sql-createforeigntable.html"
>CREATE FOREIGN TABLE</A
> for a further description of valid
    parameters.
   </P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73559"
></A
><H2
>Examples</H2
><P
>   To mark a column as not-null:
</P><PRE
CLASS="PROGRAMLISTING"
>ALTER FOREIGN TABLE distributors ALTER COLUMN street SET NOT NULL;</PRE
><P>
  </P
><P
>   To change options of a foreign table:
</P><PRE
CLASS="PROGRAMLISTING"
>ALTER FOREIGN TABLE myschema.distributors OPTIONS (ADD opt1 'value', SET opt2 'value2', DROP opt3 'value3');</PRE
><P></P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73565"
></A
><H2
>Compatibility</H2
><P
>   The forms <TT
CLASS="LITERAL"
>ADD</TT
>, <TT
CLASS="LITERAL"
>DROP</TT
>,
   and <TT
CLASS="LITERAL"
>SET DATA TYPE</TT
>
   conform with the SQL standard.  The other forms are
   <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> extensions of the SQL standard.
   Also, the ability to specify more than one manipulation in a single
   <TT
CLASS="COMMAND"
>ALTER FOREIGN TABLE</TT
> command is an extension.
  </P
><P
>   <TT
CLASS="COMMAND"
>ALTER FOREIGN TABLE DROP COLUMN</TT
> 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.
  </P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN73575"
></A
><H2
>See Also</H2
><A
HREF="sql-createforeigntable.html"
>CREATE FOREIGN TABLE</A
>, <A
HREF="sql-dropforeigntable.html"
>DROP FOREIGN TABLE</A
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="sql-alterforeigndatawrapper.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="sql-alterfunction.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>ALTER FOREIGN DATA WRAPPER</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="sql-commands.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>ALTER FUNCTION</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>