On 3/4/19, 12:11 PM, "Andres Freund" <andres@anarazel.de> wrote:
> I'm not quite convinced this is right. There's plenty sites that
> practically can't use autovacuum because it might decide to vacuum the
> 5TB index because of 300 dead tuples in the middle of busy periods. And
> without an reloption that's not controllable.
Wouldn't it be better to adjust the cost and threshold parameters or
to manually vacuum during quieter periods? I suppose setting
DISABLE_INDEX_CLEANUP on a relation during busy periods could be
useful if you really need to continue reclaiming transaction IDs, but
that seems like an easy way to accidentally never vacuum indexes.
Nathan