Re: 9.2beta1, parallel queries, ReleasePredicateLocks, CheckForSerializableConflictIn in the oprofile - Mailing list pgsql-hackers

From Sergey Koposov
Subject Re: 9.2beta1, parallel queries, ReleasePredicateLocks, CheckForSerializableConflictIn in the oprofile
Date
Msg-id alpine.LRH.2.02.1205261505050.12723@calx046.ast.cam.ac.uk
Whole thread Raw
In response to Re: 9.2beta1, parallel queries, ReleasePredicateLocks, CheckForSerializableConflictIn in the oprofile  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: 9.2beta1, parallel queries, ReleasePredicateLocks, CheckForSerializableConflictIn in the oprofile
List pgsql-hackers
On Sat, 26 May 2012, Robert Haas wrote:
> This theory is seeming fairly plausible - how can we test it?
>
> How about trying it with synchronize_seqscans = off?  If the
> synchronized-seqscan logic is causing contention on the buf mapping
> locks and individual buffer locks, that should fix it.

Turning off synch seq scans doesn't help either. 18 sec multithreaded run 
vs 7 sec single threaded.
    S

*****************************************************
Sergey E. Koposov, PhD, Research Associate
Institute of Astronomy, University of Cambridge
Madingley road, CB3 0HA, Cambridge, UK
Tel: +44-1223-337-551 Web: http://www.ast.cam.ac.uk/~koposov/


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