digoal
2023-09-06
PostgreSQL , PolarDB , snapshot too old
Remove the "snapshot too old" feature.
author Thomas Munro <tmunro@postgresql.org>
Tue, 5 Sep 2023 06:26:12 +0000 (18:26 +1200)
committer Thomas Munro <tmunro@postgresql.org>
Tue, 5 Sep 2023 07:53:43 +0000 (19:53 +1200)
commit f691f5b80a85c66d715b4340ffabb503eb19393e
tree 26a06c87096de2f9571956b4370ccbf1852d4cba tree
parent aa0d3504560d40f4300a3d49d1c6c3bfc3b894e5 commit | diff
Remove the "snapshot too old" feature.
Remove the old_snapshot_threshold setting and mechanism for producing
the error "snapshot too old", originally added by commit 848ef42b.
Unfortunately it had a number of known problems in terms of correctness
and performance, mostly reported by Andres in the course of his work on
snapshot scalability. We agreed to remove it, after a long period
without an active plan to fix it.
This is certainly a desirable feature, and someone might propose a new
or improved implementation in the future.
Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CACG%3DezYV%2BEvO135fLRdVn-ZusfVsTY6cH1OZqWtezuEYH6ciQA%40mail.gmail.com
Discussion: https://postgr.es/m/20200401064008.qob7bfnnbu4w5cw4%40alap3.anarazel.de
Discussion: https://postgr.es/m/CA%2BTgmoY%3Daqf0zjTD%2B3dUWYkgMiNDegDLFjo%2B6ze%3DWtpik%2B3XqA%40mail.gmail.com
