On Sat, Nov 4, 2017 at 4:43 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Paul Ramsey <pram...@cleverelephant.ca> writes: >>> Whether I get a parallel aggregate seems entirely determined by the number >>> of rows, not the cost of preparing those rows. > >> This is true, as far as I can tell and unfortunate. Feeding tables with >> 100ks of rows, I get parallel plans, feeding 10ks of rows, never do, no >> matter how costly the work going on within. That's true of changing costs >> on the subquery select list, and on the aggregate transfn. > > This sounds like it might be the same issue being discussed in > > https://www.postgresql.org/message-id/flat/CAMkU=1ycXNipvhWuweUVpKuyu6SpNjF=yhwu4c4us5jgvgx...@mail.gmail.com >
I have rebased the patch being discussed on that thread. Paul, you might want to once check with the recent patch [1] posted on the thread mentioned by Tom. [1] - https://www.postgresql.org/message-id/CAA4eK1%2B1H5Urm0_Wp-n5XszdLX1YXBqS_zW0f-vvWKwdh3eCJA%40mail.gmail.com -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
