Re: Proposal: Improve bitmap costing for lossy pages
Dilip Kumar <dilipbalaut@gmail.com>
From: Dilip Kumar <dilipbalaut@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Alexander Kumenkov <a.kuzmenkov@postgrespro.ru>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-10-06T14:04:16Z
Lists: pgsql-hackers
Attachments
- improve_bitmap_cost_v5.patch (application/octet-stream) patch v5
On Fri, Oct 6, 2017 at 7:04 PM, Dilip Kumar <dilipbalaut@gmail.com> wrote: > On Fri, Oct 6, 2017 at 6:36 PM, Robert Haas <robertmhaas@gmail.com> wrote: >> On Fri, Oct 6, 2017 at 2:12 AM, Dilip Kumar <dilipbalaut@gmail.com> wrote: >>>> The performance results look good, but that's a slightly different >>>> thing from whether the estimate is accurate. >>>> >>>> + nbuckets = tbm_calculate_entires(maxbytes); >>>> >>>> entires? >>> >>> changed to >>> + tbm->maxentries = (int) tbm_calculate_entires(maxbytes); >> >> My point was not that you should add a cast, but that you wrote >> "entires" rather than "entries". > > My bad, I thought you were suggesting the variable name as "entries" > instead of "nbuckets" so I removed the variable "nbuckets". I will > fix the typo in the function name and post the patch. Fixed in the attached version. -- Regards, Dilip Kumar EnterpriseDB: http://www.enterprisedb.com
Commits
-
Account for the effect of lossy pages when costing bitmap scans.
- 5edc63bda68a 11.0 landed