On Wed, Mar 16, 2016 at 5:41 AM, Constantin S. Pan <kva...@gmail.com> wrote:
> On Mon, 14 Mar 2016 08:42:26 -0400 > David Steele <da...@pgmasters.net> wrote: > > > On 2/18/16 10:10 AM, Constantin S. Pan wrote: > > > On Wed, 17 Feb 2016 23:01:47 +0300 > > > Oleg Bartunov <obartu...@gmail.com> wrote: > > > > > >> My feedback is (Mac OS X 10.11.3) > > >> > > >> set gin_parallel_workers=2; > > >> create index message_body_idx on messages using gin(body_tsvector); > > >> LOG: worker process: parallel worker for PID 5689 (PID 6906) was > > >> terminated by signal 11: Segmentation fault > > > > > > Fixed this, try the new patch. The bug was in incorrect handling > > > of some GIN categories. > > > > Oleg, it looks like Constantin has updated to patch to address the > > issue you were seeing. Do you have time to retest and review? > > > > Thanks, > > Actually, there was some progress since. The patch is > attached. > > 1. Added another GUC parameter for changing the amount of > shared memory for parallel GIN workers. > > 2. Changed the way results are merged. It uses shared memory > message queue now. > > 3. Tested on some real data (GIN index on email message body > tsvectors). Here are the timings for different values of > 'gin_shared_mem' and 'gin_parallel_workers' on a 4-CPU > machine. Seems 'gin_shared_mem' has no visible effect. > > wnum mem(MB) time(s) > 0 16 247 > 1 16 256 > It seems from you data that with 1 worker, you are always seeing slowdown, have you investigated the reason of same? With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
