ALTER INDEX(7)                                            SQL Commands                                            ALTER INDEX(7)



NAME
       ALTER INDEX - change the definition of an index


SYNOPSIS
       ALTER INDEX name RENAME TO new_name
       ALTER INDEX name SET TABLESPACE tablespace_name
       ALTER INDEX name SET ( storage_parameter = value [, ... ] )
       ALTER INDEX name RESET ( storage_parameter [, ... ] )


DESCRIPTION
       ALTER INDEX changes the definition of an existing index.  There are several subforms:

       RENAME The RENAME form changes the name of the index.  There is no effect on the stored data.

       SET TABLESPACE
              This  form  changes  the index's tablespace to the specified tablespace and moves the data file(s) associated with
              the index to the new tablespace.  See also CREATE TABLESPACE [create_tablespace(7)].

       SET ( storage_parameter = value [, ... ] )
              This form changes one or more index-method-specific storage parameters for  the  index.  See  CREATE  INDEX  [cre-
              ate_index(7)]  for  details on the available parameters. Note that the index contents will not be modified immedi-
              ately by this command; depending on the parameter you might need to rebuild the index with REINDEX [reindex(7)] to
              get the desired effects.

       RESET ( storage_parameter [, ... ] )
              This  form  resets  one or more index-method-specific storage parameters to their defaults. As with SET, a REINDEX
              might be needed to update the index entirely.

PARAMETERS
       name   The name (possibly schema-qualified) of an existing index to alter.

       new_name
              The new name for the index.

       tablespace_name
              The tablespace to which the index will be moved.

       storage_parameter
              The name of an index-method-specific storage parameter.

       value  The new value for an index-method-specific storage parameter.  This might be a number or a word depending  on  the
              parameter.

NOTES
       These  operations  are  also  possible  using ALTER TABLE [alter_table(7)].  ALTER INDEX is in fact just an alias for the
       forms of ALTER TABLE that apply to indexes.

       There was formerly an ALTER INDEX OWNER variant, but this is now ignored (with a warning). An index cannot have an  owner
       different from its table's owner. Changing the table's owner automatically changes the index as well.

       Changing any part of a system catalog index is not permitted.

EXAMPLES
       To rename an existing index:

       ALTER INDEX distributors RENAME TO suppliers;


       To move an index to a different tablespace:

       ALTER INDEX distributors SET TABLESPACE fasttablespace;


       To change an index's fill factor (assuming that the index method supports it):

       ALTER INDEX distributors SET (fillfactor = 75);
       REINDEX INDEX distributors;


COMPATIBILITY
       ALTER INDEX is a PostgreSQL extension.

SEE ALSO
       CREATE INDEX [create_index(7)], REINDEX [reindex(7)]



SQL - Language Statements                                  2011-09-22                                             ALTER INDEX(7)