Re: compute_query_id and pg_stat_statements

On Thu, May 13, 2021 at 08:32:50AM -0700, Maciek Sakrejda wrote:
> > Well, now that we have clear warnings when it is misconfigured,
> > especially when querying the pg_stat_statements view, are these
> > complaints still valid? Also, how is modifying
> > shared_preload_libraries zero-config, but modifying
> > shared_preload_libraries and compute_query_id a huge burden?
>
> The warning makes it clear that there's something wrong, but not how
> to fix it (as I noted in another message in this thread, a web search
> for pg_stat_statements docs still leads to an obsolete version). I
> don't think anyone is arguing that this is insurmountable for all
> users, but it is additional friction, and every bit of friction makes
> Postgres harder to use. Users don't read documentation, or misread
> documentation, or just are not sure what the documentation or the
> warning is telling them, in spite of our best efforts.

Well, then let's have the error message tell them what is wrong and how
to fix it. My issue is that 'auto' spreads confusion around the entire
API, as you can see from the discussion in this thread.

> And you're right, modifying shared_preload_libraries is not
> zero-config--I would love it if we could drop that requirement ;).
> Still, adding another setting is clearly one more thing to get wrong.
>
> > I am personally not comfortable committing a patch to add an auto option
> > the way it is implemented, so another committer will need to take
> > ownership of this, or the entire feature can be removed.
>
> Assuming we do want to avoid additional configuration requirements for
> pg_stat_statements, is there another mechanism you feel would work
> better? Or is that constraint incompatible with sane behavior for this
> feature?

I think we just need to leave it is on/off, and then help people find
the way to fix it if the misconfigure it, which I think is already been
shown to be possible.

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

If only the physical world exists, free will is an illusion.