ALTER INDEX
  7
  SQL - Language Statements
 
 
  ALTER INDEX
  change the definition of an index
 
 
  ALTER INDEX
 
 
ALTER INDEX [ IF EXISTS ] name RENAME TO new_name
ALTER INDEX [ IF EXISTS ] name SET TABLESPACE tablespace_name
ALTER INDEX [ IF EXISTS ] name SET ( storage_parameter = value [, ... ] )
ALTER INDEX [ IF EXISTS ] name RESET ( storage_parameter [, ... ] )
 
 
  Description
  
   ALTER INDEX changes the definition of an existing index.
   There are several subforms:
  
   
    IF EXISTS
    
     
      Do not throw an error if the index does not exist. A notice is issued
      in this case.
     
    
   
   
    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
      .
     
    
   
   
    SET ( storage_parameter = value [, ... ] )
    
     
      This form changes one or more index-method-specific storage parameters
      for the index.  See
      
      for details on the available parameters.  Note that the index contents
      will not be modified immediately by this command; depending on the
      parameter you might need to rebuild the index with
      
      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 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