On Thu, Apr 15, 2021 at 03:43:59PM +0800, Julien Rouhaud wrote:
> On Mon, Apr 12, 2021 at 02:56:59PM +0800, Julien Rouhaud wrote:
> > I think we should simply document that %Q is not compatible with
> > log_statements.
>
> Hearing no objection I documented that limitation.
>
> >
> > > While making the feature run on some test server, I have noticed that
> > > %Q would log some garbage query ID for autovacuum workers that's kept
> > > around. That looks wrong.
> >
> > I've not been able to reproduce it, do you have some hint on how to do it?
> >
> > Maybe setting a zero queryid at the beginning of AutoVacWorkerMain() could
> > fix
> > the problem?
>
> It turns out that the problem was simply that some process can inherit a
> PgBackendStatus for which a previous backend reported a queryid. For
> processes
> like autovacuum process, they will never report a new identifier so they
> reported the previous one. Resetting the field like the other ones in
> pgstat_bestart() fixes the problem for autovacuum and any similar process.
I slightly adjusted the patch and applied it. Thanks. I think this
closes all the open issues around query_id. :-)
--
Bruce Momjian <br...@momjian.us> https://momjian.us
EDB https://enterprisedb.com
If only the physical world exists, free will is an illusion.
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 776ab1a8c8..dd7ebe7a9d 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7139,6 +7139,16 @@ log_line_prefix = '%m [%p] %q%u@%d/%a '
</programlisting>
</para>
</tip>
+
+ <note>
+ <para>
+ The <literal>%Q</literal> escape always reports a zero identifier
+ for lines output by <xref linkend="guc-log-statement"/> because
+ <varname>log_statement</varname> generates output before an
+ identifier can be calculated, including invalid statements for
+ which an identifier cannot be calculated.
+ </para>
+ </note>
</listitem>
</varlistentry>
diff --git a/src/backend/utils/activity/backend_status.c b/src/backend/utils/activity/backend_status.c
index 787f062f9c..a368101103 100644
--- a/src/backend/utils/activity/backend_status.c
+++ b/src/backend/utils/activity/backend_status.c
@@ -398,6 +398,7 @@ pgstat_bestart(void)
lbeentry.st_state = STATE_UNDEFINED;
lbeentry.st_progress_command = PROGRESS_COMMAND_INVALID;
lbeentry.st_progress_command_target = InvalidOid;
+ lbeentry.st_query_id = UINT64CONST(0);
/*
* we don't zero st_progress_param here to save cycles; nobody should
