Re: increasing the default WAL segment size

On Tue, Mar 21, 2017 at 11:49:30PM -0400, Robert Haas wrote:
> To be honest, I'd sort of forgotten about the change which is the
> nominal subject of this thread - I was more focused on the patch,
> which makes it configurable. I was definitely initially in favor of
> raising the value, but I got cold feet, a bit, when Alvaro pointed out
> that going to 64MB would require a substantial increase in
> min_wal_size. I'm not sure people with small installations will
> appreciate seeing that value cranked up from 5 segments * 16MB = 80MB
> to, say, 3 segments * 64MB = 192MB. That's an extra 100+ MB of space
> that doesn't really do anything for you. And nobody's done any
> benchmarking to see whether having only 3 segments is even a workable,
> performant configuration, so maybe we'll end up with 5 * 64MB = 320MB
> by default.

Maybe its time to have a documentation section listing suggested changes
for small installs so we can have more reasonable defaults.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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