Re:Improved vacuum in PostgreSQL 13
by hu3 on Tuesday May 12, 2020 @03:19AM
(#23151332)
Does it affect performance?
I might not want VACUUM to trigger during high workload.
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Re:Improved vacuum in PostgreSQL 13
by hans_castorp on Tuesday May 12, 2020 @04:11AM
(#23151611)
Yes it does, it makes things faster ;)
A common misconception about (auto) vacuum is, that you need to turn it off, to avoid performance problems.
The truth is: you need to make it more aggressive (= run it more frequently) if you have problems with the (additional) I/O load it generates.
Obviously I meant to ask if performance is affected during VACUUM.
@pg-gadfly's link answered it for me:
> VACUUM creates a substantial amount of I/O traffic, which can cause poor performance for other active sessions.
Since a vacuum operation uses processor cycles, it's impossible to say no.
Their wiki is pretty amazing source for postgres's operation: https://www.postgresql.org/docs/12/routine-vacuuming.html