Tom Lane napisał(a):
Marcin Giedz <marcin.giedz@xxxxxxxxxxxxxx> writes:
However I still can see 'spikey' performance but not as much as before
changes. What can I do more to eliminate or smooth these spikes?
The spikes are certainly caused by checkpoints. You can fool with the
checkpoint timing via checkpoint_segments and checkpoint_timeout.
I didn't mention before but I changed checkpoint_segments to 300 but no
checkpoint_time. Disk space doesn't matter at all ... time to
recovery.... shouldn't be very long (I don't have much experiences with
this as I do online backup every day). Can anyone please tell me what
values of these two parametres are reasonable?
Regards,
Marcin
Usually people put them as far apart as they can stand (the constraint
on this is mainly how long you'd like to wait for recovery after a
system crash, and how much disk space you can spare for WAL logs).
Increasing the bg_writer parameters can be expected to dampen the spikes
but not eliminate them completely.
regards, tom lane
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