On 07/13/2017 04:36 PM, Adrien Nayrat wrote: > Hello hackers, > > From: Peter Geoghegan <p...@bowt.ie> >> Date: Wed, 5 Jul 2017 15:19:57 -0700 >> Subject: Re: [BUGS] BUG #14722: Segfault in tuplesort_heap_siftup, 32 bit >> overflow >> On pgsql-b...@postgresql.org > > On 07/06/2017 12:19 AM, Peter Geoghegan wrote: >> In Postgres 10, tuplesort external sort run merging became much faster >> following commit 24598337c8d. It might be noticeable if such a machine >> were using Postgres 10 [...] > > Should-we mention this improvement in release notes? > > Regards, >
Hello, After seeing theses slides (especially 52) : https://speakerdeck.com/peterg/sort-hash-pgconfus-2017 I noticed several commits which improves performance of hash tables. Commit's messages mentions performance improvements for bitmap scans, hash aggregation and (according to Peter Geoghegan's conference) hash join : commit b30d3ea824c5ccba43d3e942704f20686e7dbab8 Author: Andres Freund <and...@anarazel.de> Date: Fri Oct 14 16:05:30 2016 -0700 Add a macro templatized hashtable. [...] In queries where these use up a large fraction of the time, this has been measured to lead to performance improvements of over 100%. commit 75ae538bc3168bf44475240d4e0487ee2f3bb376 Author: Andres Freund <and...@anarazel.de> Date: Fri Oct 14 16:05:30 2016 -0700 Use more efficient hashtable for tidbitmap.c to speed up bitmap scans. [...] For bitmap scan heavy queries speedups of over 100% have been measured. commit 5dfc198146b49ce7ecc8a1fc9d5e171fb75f6ba5 Author: Andres Freund <and...@anarazel.de> Date: Fri Oct 14 17:22:51 2016 -0700 Use more efficient hashtable for execGrouping.c to speed up hash aggregation. [...] Improvements of over 120% have been measured. Should we mention it ? Regards, -- Adrien NAYRAT http://dalibo.com - http://dalibo.org
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