Re: restore time: sort_mem vs. checkpoing_segments - Mailing list pgsql-performance

From Tom Lane
Subject Re: restore time: sort_mem vs. checkpoing_segments
Date
Msg-id 14070.1063689540@sss.pgh.pa.us
Whole thread Raw
In response to restore time: sort_mem vs. checkpoing_segments  (Vivek Khera <khera@kcilink.com>)
Responses Re: restore time: sort_mem vs. checkpoing_segments
List pgsql-performance
Vivek Khera <khera@kcilink.com> writes:
> Restore of a significanly big database (~19.8GB restored) shows nearly
> no time difference depending on sort_mem when checkpoint_segments is
> large.  There are quite a number of tables and indexes.  The restore
> was done from a pg_dump -Fc dump of one database.

I was just bugging Marc for some useful data, so I'll ask you too:
could you provide a trace of the pg_restore execution?  log_statement
plus log_duration output would do it.  I am curious to understand
exactly which steps in the restore are significant time sinks.

> I notice during the restore that the disk throughput triples during
> the checkpoint.

Hm, better make sure the log includes some indication of when
checkpoints happen.

            regards, tom lane

pgsql-performance by date:

Previous
From: Christopher Browne
Date:
Subject: Re: Inconsistent performance
Next
From: Manfred Koizar
Date:
Subject: Re: Inconsistent performance