Thread: BUG #17665: pg_stat_statements useless with variable number of parameters in IN close

The following bug has been logged on the website:

Bug reference:      17665
Logged by:          Sebastien Caunes
Email address:      bokanist@gmail.com
PostgreSQL version: 15.0
Operating system:   all
Description:

Not really a bug, but this issue makes pg_stat_statements almost useless.

One of my customer have queries with variables number of parameters in IN
closes

SELECT * FROM my_table WHERE id IN ($1, $2, $3, $4, ...) -- number of
parameters varies from one to thousands

And some queries have more than one IN close. This bloat the
pg_stat_statement table with all different version of the same query.

I think the parameters in IN close should be merged as one.
By the way, where should I submit this kind of improvement request ?

Hi,

On Thu, Oct 27, 2022 at 10:42:52AM +0000, PG Bug reporting form wrote:
>
> Not really a bug, but this issue makes pg_stat_statements almost useless.
>
> One of my customer have queries with variables number of parameters in IN
> closes
>
> SELECT * FROM my_table WHERE id IN ($1, $2, $3, $4, ...) -- number of
> parameters varies from one to thousands
>
> And some queries have more than one IN close. This bloat the
> pg_stat_statement table with all different version of the same query.
>
> I think the parameters in IN close should be merged as one.
> By the way, where should I submit this kind of improvement request ?

I agree, and this is a known problem however it isn't as simple to fix as it
looks.  You can find the latest discussion about it at
https://www.postgresql.org/message-id/flat/CA%2Bq6zcWtUbT_Sxj0V6HY6EZ89uv5wuG5aefpe_9n0Jr3VwntFg%40mail.gmail.com
if you want more details or participate.