Re: When do vacuumed pages/tuples become available for reuse?

On 2019-Apr-11, rihad wrote:

> On 04/11/2019 06:20 PM, Tom Lane wrote:
> > rihad <rihad(at)mail(dot)ru> writes:
> > > Thanks! Our autovacuum_work_mem = 1GB, so this probably means any space
> > > would be available for reuse only at the end of the vacuum?
> > It's six bytes per dead tuple, last I checked ... you do the math.
> >
> > > Are there
> > > any downsides in decreasing it to, say, 64MB? I see only pluses )
> > Well, usually people prefer to minimize the number of passes over
> > the indexes.

> Yup, it's just that n_dead_tuples grows by several hundred thousand (the
> table sees much much more updates than inserts) and disk usage grows
> constantly between several hour long vacuum runs. Running vacuum full isn't
> an option.

Perhaps it'd be better to vacuum this table much more often.

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Álvaro Herrera https://www.2ndQuadrant.com/
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