On 2020-Jun-08, Tomas Vondra wrote:
> Not sure if it's sufficient, though, because switching to logical may
> require bumping up number of slots, walsenders, etc. At which point you
> actually need a restart. Not to mention that extensions using logical
> decoding (like pglogical) need to allocate shared memory etc. But for
> the built-in logical replication that is not an issue, ofc.
I think it's reasonable to push our default limits for slots,
walsenders, max_bgworkers etc a lot higher than current value (say 10 ->
100). An unused slot wastes essentially no resources; an unused
walsender is just one PGPROC entry. If we did that, and also allowed
wal_level to be changed on the fly, we wouldn't need to restart in order
to enable logical replication, so there would be little or no pressure
to change the wal_level default.
--
Álvaro Herrera https://www.2ndQuadrant.com/
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