Re: pg_stat_statements and "IN" conditions

On Mon, 3 Mar 2025 at 17:26, Álvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
>
> On 2025-Feb-18, Sami Imseih wrote:
>
> > > It's not a question about whether it's possible to implement this,
> > > but about whether it makes sense. In case of plain constants it's
> > > straightforward -- they will not change anything meaningfully and
> > > hence could be squashed from the query. Now for a function, that
> > > might return different values for the same set of constant
> > > arguments, it's much less obvious and omitting such expressions
> > > might have unexpected consequences.
> >
> > query jumbling should not care about the behavior of the function. If
> > we take a regular call to a volatile function, we will generate the
> > same queryId for every call regardless of the input to the function.
> > Why does the in-list case need to care about the volatility of the
> > function?
>
> I feel quite insecure about this idea TBH. At least with immutable
> functions I don't expect the system to behave wildly different than with
> actual constants. What non-immutable functions do you have in mind that
> would be useful to fold as if they were constants in the IN list in such
> a query?
>
> In the meantime, here's v28 which is Dmitry's v27 plus pgindent. No
> other changes. Dmitry, were you planning to submit a new version?

I noticed that the feedback from Sami at [1] has not yet been
addressed, I have changed the status to Waiting on Author, kindly
address them and update the status to Needs review.
[1] - https://www.postgresql.org/message-id/CAA5RZ0vt29Om%2BtKFOcUNhXV%2BkKpNnj0yj6OFho3-wngcMHWnAQ%40mail.gmail.com

Regards,
Vignesh