From f691f5b80a85c66d715b4340ffabb503eb19393e Mon Sep 17 00:00:00 2001 From: Thomas Munro Date: Tue, 5 Sep 2023 18:26:12 +1200 Subject: 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 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 --- src/backend/utils/misc/guc_tables.c | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'src/backend/utils/misc/guc_tables.c') diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c index e565a3092f6..4107d0a7355 100644 --- a/src/backend/utils/misc/guc_tables.c +++ b/src/backend/utils/misc/guc_tables.c @@ -3282,17 +3282,6 @@ struct config_int ConfigureNamesInt[] = check_autovacuum_work_mem, NULL, NULL }, - { - {"old_snapshot_threshold", PGC_POSTMASTER, RESOURCES_ASYNCHRONOUS, - gettext_noop("Time before a snapshot is too old to read pages changed after the snapshot was taken."), - gettext_noop("A value of -1 disables this feature."), - GUC_UNIT_MIN - }, - &old_snapshot_threshold, - -1, -1, MINS_PER_HOUR * HOURS_PER_DAY * 60, - NULL, NULL, NULL - }, - { {"tcp_keepalives_idle", PGC_USERSET, CONN_AUTH_TCP, gettext_noop("Time between issuing TCP keepalives."), -- cgit v1.2.3