Hi Everyone
I just want to illustrate an idea may possible for bringing up
parallel process in PostgreSQL at SQL-Query level
The PARALLEL option in Oracle really give great improvment in
performance, multi-thread concept has great possibilities
In Oracle we have hints ( see below ) :
SELECT /*+PARALLEL( e, 2 )*/ e.* FROM EMP e ;
PostgreSQL ( may if possible in future ) :
SELECT e.* FROM EMP PARALLEL ( e, 2) ;
*Note: The below syntax does not work with any PostgreSQL versions
PostgreSQL Syntax for SELECT ( with PARALLEL )
[ WITH [ RECURSIVE ] with_query [, ...] ]
SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ]
* | expression [ [ AS ] output_name ] [, ...]
[ FROM from_item [, ...] ]
[ WHERE condition ]
[ GROUP BY expression [, ...] ]
[ HAVING condition [, ...] ]
[ WINDOW window_name AS ( window_definition ) [, ...] ]
[ PARALLEL (<alias> | <table> | <index> |<segment> , < no. of threads> ) ]
[ { UNION | INTERSECT | EXCEPT } [ ALL ] select ]
[ ORDER BY expression [ ASC | DESC | USING operator ] [ NULLS {
FIRST | LAST } ] [, ...] ]
[ LIMIT { count | ALL } ]
[ OFFSET start [ ROW | ROWS ] ]
[ FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ]
[ FOR { UPDATE | SHARE } [ OF table_name [, ...] ] [ NOWAIT ] [...] ]
On 1/24/12, ashish nauriyal <anauriyal@gmail.com> wrote:
> Thoughts by Bruce Momjian on Parallel execution in PostgreSQL...
>
> http://momjian.us/main/blogs/pgblog/2011.html#December_5_2011
>
> You can give your thoughts on the blog itself....
>
> Thanks,
> Ashish Nauriyal
>