Re: Pg10 : Client Configuration for Parallelism ?

From: Thomas Kellerer <spam_eater(at)gmx(dot)net>
To: pgsql-performance(at)lists(dot)postgresql(dot)org
Subject: Re: Pg10 : Client Configuration for Parallelism ?
Date: 2019-04-19 06:52:24
Message-ID: 3f3cbd47-f154-7e63-94c7-66a0bf8c4a27@gmx.net
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laurent(dot)dechambe(at)orange(dot)com schrieb am 17.04.2019 um 16:33:
> Hello Justin and thank you for your clues.
>
> Finally I found that putting blank to the option that limits the
> number of rows to retrieve (which is normal for this kind of tool)
> allows PostgreSQL to parallelize the query.
>
> On jdbc it seems this is equivalent to write :
> statement. setMaxRows(0); // parallelism authorized, which is the default.
>
> Thus on my jdbc basic program if I add :
> statement. setMaxRows(100); // No parallelism allowed (at least in Pg10)
>
> Thanks to all who were kind enough to help.

This isn't limited to Statement.setMaxRows()

If you use "LIMIT x" in your SQL query, the same thing happens.

Thomas

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