Oracle Parallel Query Option FAQ

$Date: 13-Dec-1996 $
$Revision: 1.0 $
$Author: Frank Naudé $

Topics

This option is mainly used for performance reasons and is commonly seen in Decision Support and Data Warehousing applications.

• ALTER your table (or index) and indicating that it is a parallel table

ALTER TABLE TAB_XXX PARALLEL (DEGREE 7);

• putting hints in your SQL statement to indicate that it should be executed in parallel
  

  SELECT --+ PARALLEL(table_alias, degree, nodes) * FROM table ...

ALTER TABLE TAB_XXX PARALLEL (DEGREE 1 INSTANCES 1); or
ALTER TABLE TAB_XXX NOPARALLEL;

ALTER INDEX IND_XXX PARALLEL (DEGREE 1 INSTANCES 1); or
ALTER INDEX IND_XXX NOPARALLEL;

• PARALLEL_MIN_SERVERS
• PARALLEL_MAX_SERVERS
• etc.

select * from sys.v_$pq_sysstat;

select * from v_$pq_sysstat;
select * from v_$px_process;
select * from v_$px_sesstat;
select * from v_$px_process_sysstat;