Re: BUG #15290: Stuck Parallel Index Scan query
Amit Kapila <amit.kapila16@gmail.com>
From: Amit Kapila <amit.kapila16@gmail.com>
To: Victor Yegorov <vyegorov@gmail.com>
Cc: Thomas Munro <thomas.munro@enterprisedb.com>, PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Date: 2018-07-27T05:47:49Z
Lists: pgsql-bugs
On Thu, Jul 26, 2018 at 3:53 PM, Victor Yegorov <vyegorov@gmail.com> wrote: > ср, 25 июл. 2018 г. в 8:46, Amit Kapila <amit.kapila16@gmail.com>: >> >> On Wed, Jul 25, 2018 at 8:43 AM, Amit Kapila <amit.kapila16@gmail.com> >> wrote: >> > Well spotted. I think here we can release the current page lock >> > before calling _bt_parallel_seize as we don't need it to get the next >> > page. >> > >> >> I have written a patch on the above lines and manually verified (by >> reproducing the issue via debugger) that it fixes the issue. Thomas, >> Victor, is it possible for you guys to see if the attached fixes the >> issue for you? > > > First, I failed to reproduce Thomas' case on the VM with just 1 core. > But it is reproduced just fine on an 8-core machine, make sure to warm up > the index first though. > > Patch fixes the issue for me here. > Thanks, pushed the fix. I have not included Thomas's test as it is timing dependent and it seems risky to include such a test. -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
Commits
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Fix the buffer release order for parallel index scans.
- ff8ce0b79009 10.5 landed
- 8ce29bb4f0df 12.0 landed