From d9484ab5f3cbcfea64536fec333723f9aa4c0b2c Mon Sep 17 00:00:00 2001 From: Alvaro Herrera <alvherre@alvh.no-ip.org> Date: Thu, 28 Nov 2013 16:45:29 -0300 Subject: [PATCH] Replace hardcoded 200000000 with autovacuum_freeze_max_age Parts of the code used autovacuum_freeze_max_age to determine whether anti-multixact-wraparound vacuums are necessary, while others used a hardcoded 200000000 value. This leads to problems when autovacuum_freeze_max_age is set to a non-default value. Use the latter everywhere. Backpatch to 9.3, where vacuuming of multixacts was introduced. Andres Freund --- src/backend/access/transam/multixact.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c index e3f5cbc0cd..de0193aaf6 100644 --- a/src/backend/access/transam/multixact.c +++ b/src/backend/access/transam/multixact.c @@ -74,6 +74,7 @@ #include "funcapi.h" #include "miscadmin.h" #include "pg_trace.h" +#include "postmaster/autovacuum.h" #include "storage/lmgr.h" #include "storage/pmsignal.h" #include "storage/procarray.h" @@ -1958,6 +1959,10 @@ SetMultiXactIdLimit(MultiXactId oldest_datminmxid, Oid oldest_datoid) /* * We'll refuse to continue assigning MultiXactIds once we get within 100 * multi of data loss. + * + * Note: This differs from the magic number used in + * SetTransactionIdLimit() since vacuum itself will never generate new + * multis. */ multiStopLimit = multiWrapLimit - 100; if (multiStopLimit < FirstMultiXactId) @@ -1979,9 +1984,12 @@ SetMultiXactIdLimit(MultiXactId oldest_datminmxid, Oid oldest_datoid) /* * We'll start trying to force autovacuums when oldest_datminmxid gets to - * be more than 200 million transactions old. + * be more than autovacuum_freeze_max_age mxids old. + * + * It's a bit ugly to just reuse limits for xids that way, but it doesn't + * seem worth adding separate GUCs for that purpose. */ - multiVacLimit = oldest_datminmxid + 200000000; + multiVacLimit = oldest_datminmxid + autovacuum_freeze_max_age; if (multiVacLimit < FirstMultiXactId) multiVacLimit += FirstMultiXactId; -- 2.40.0