Re: Feature improvement: can we add queryId for pg_catalog.pg_stat_activity view?

On Tue, Jul 28, 2020 at 10:07 AM torikoshia <torikoshia(at)oss(dot)nttdata(dot)com> wrote:
>
> Thanks for updating!
> I tested the patch setting log_statement = 'all', but %Q in
> log_line_prefix
> was always 0 even when pg_stat_statements.queryid and
> pg_stat_activity.queryid are not 0.
>
> Is this an intentional behavior?
>
>[...]

Thanks for the tests! That's indeed an expected behavior (although I
wasn't aware of it), which isn't documented in this patch (I'll fix
it). The reason for that is that log_statements is done right after
parsing the query:

/*
* Do basic parsing of the query or queries (this should be safe even if
* we are in aborted transaction state!)
*/
parsetree_list = pg_parse_query(query_string);

/* Log immediately if dictated by log_statement */
if (check_log_statement(parsetree_list))
{
ereport(LOG,
(errmsg("statement: %s", query_string),
errhidestmt(true),
errdetail_execute(parsetree_list)));
was_logged = true;
}

As parse analysis is not yet done, no queryid can be computed at that
point, so we always print 0. That's a limitation that can't be
removed without changing the semantics of log_statements, so we'll
probably have to live with it.

> And here is a minor typo.
> optionnally -> optionally
>
>
> > 753 + /* query identifier, optionnally computed using
> > post_parse_analyze_hook */

Thanks, I fixed it locally!