Re: Finding out if 'vacuum --analyze-in-stages' has generated enough stats

On Wed, Mar 31, 2021 at 12:38:14PM +0530, Vineet Naik wrote:
> > This option will try to create some statistics as fast as possible, to make the database usable, and then produce full statistics in the subsequent stages.
>
> So my question is, after which stage is it ok to send traffic to the
> server without much performance impact? Also, is it possible to query
> the stats view in pg and determine if enough stats have been
> generated?

That is a very hard question to answer. Some queries have only a few
possible plans, so few or no statistics are fine. Other queries require
detailed statistics to generate efficient plans. I think you need to
set up a dummy server with no stats and try your workload on that, then
run the stages manually and test after each stage to see how the
performance is.

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Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

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