On 04/11/2019 06:41 PM, Alvaro Herrera wrote:
On 2019-Apr-11, rihad wrote:
On 04/11/2019 06:20 PM, Tom Lane wrote:
rihad <rihad@xxxxxxx> 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.
Each run took 5-6 hours, now it takes 2-3 hours after I've tweaked some
cost-based vacuum knobs.
