Date: Thu, 30 Sep 2021 17:09:57 +0200
From: Dmitry Dolgov <9erthalion6@gmail.com>
To: Zhihong Yu <zyu@yugabyte.com>
Cc: David Steele <david@pgmasters.net>,
	PostgreSQL-development <pgsql-hackers@postgresql.org>,
	Tom Lane <tgl@sss.pgh.pa.us>, Greg Stark <stark@mit.edu>,
	Pavel Trukhanov <pavel.trukhanov@gmail.com>
Subject: Re: pg_stat_statements and "IN" conditions
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> On Thu, Sep 30, 2021 at 08:03:16AM -0700, Zhihong Yu wrote:
> On Thu, Sep 30, 2021 at 6:49 AM Dmitry Dolgov <9erthalion6@gmail.com> wrote:
>
> > >On Wed, Jun 16, 2021 at 04:02:12PM +0200, Dmitry Dolgov wrote:
> > >
> > > > I've prepared a new rebased version to deal with the new way of
> > > > computing query id, but as always there is one tricky part. From what I
> > > > understand, now an external module can provide custom implementation
> > for
> > > > query id computation algorithm. It seems natural to think this
> > machinery
> > > > could be used instead of patch in the thread, i.e. one could create a
> > > > custom logic that will enable constants collapsing as needed, so that
> > > > same queries with different number of constants in an array will be
> > > > hashed into the same record.
> > > >
> > > > But there is a limitation in how such queries will be normalized
> > > > afterwards — to reduce level of surprise it's necessary to display the
> > > > fact that a certain query in fact had more constants that are showed in
> > > > pgss record. Ideally LocationLen needs to carry some bits of
> > information
> > > > on what exactly could be skipped, and generate_normalized_query needs
> > to
> > > > understand that, both are not reachable for an external module with
> > > > custom query id logic (without replicating significant part of the
> > > > existing code). Hence, a new version of the patch.
> > >
> > > Forgot to mention a couple of people who already reviewed the patch.
> >
> > And now for something completely different, here is a new patch version.
> > It contains a small fix for one problem we've found during testing (one
> > path code was incorrectly assuming find_const_walker results).
> >
> Hi,
>
> bq. and at position further that specified threshold.
>
>  that specified threshold -> than specified threshold

You mean in the patch commit message, nowhere else, right? Yep, my spell
checker didn't catch that, thanks for noticing!