Re: truncating pg_multixact/members

Alvaro Herrera escribió:

> So here are two patches -- the first one, for 9.3 and HEAD, introduce
> the new aging variables and use them throughout vacuum and autovacuum,
> including per-table options; the second one adjusts the struct
> declarations to avoid the ABI break in VacuumStmt and StdRdOptions.

I forgot to ask: what opinions are there about
vacuum_multixact_freeze_table_age's default value? Right now I have 150
million, same as for Xids. However, it might make sense to use 300
millions, so that whole-table scans are not forced earlier than for Xids
unless consumption rate for multixacts is double the one for Xids.

I already have set autovacuum_multixact_freeze_max_age to 400 million,
i.e. double that for Xids. This means emergency vacuums will not take
place for multis, unless consumption rate is double that for Xids.
This seems pretty reasonable to me.

--
Álvaro Herrera http://www.2ndQuadrant.com/
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