ALTER INDEX — change the definition of an index
ALTER INDEXnameRENAME TOnew_nameALTER INDEXnameSET TABLESPACEtablespace_nameALTER INDEXnameSET (storage_parameter=value[, ... ] ) ALTER INDEXnameRESET (storage_parameter[, ... ] )
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 TABLESPACEThis 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.
SET ( storage_parameter = value [, ... ] )This form changes one or more index-method-specific storage parameters for the index. See CREATE INDEX for details on the available parameters. Note that the index contents will not be modified immediately by this command; depending on the parameter you may need to rebuild the index with REINDEX 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
may be needed to update the index entirely.
nameThe name (possibly schema-qualified) of an existing index to alter.
new_nameNew name for the index.
tablespace_nameThe tablespace to which the index will be moved.
storage_parameterThe name of an index-method-specific storage parameter.
valueThe new value for an index-method-specific storage parameter. This might be a number or a word depending on the parameter.
These operations are also possible using
ALTER TABLE.
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.
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;