Re: BUG #16035: STATEMENT_TIMEOUT not working when we have single quote usage inside CTE which is used in inner sql

I wrote:
> Tatsuo Ishii <ishii@sraoss.co.jp> writes:
>> With attached patch (against master), SET STATEMENT_TIMEOUT
>> immediately affects to subsequent commands in the multi statement. I
>> think this is not only more intuitive than v10's behavior but it meets
>> the original reporter's expectation.

> Hm.  So, okay, that is a nicer API probably, but note that it also
> has the effect that the timeout starts over again for each statement
> in the string, while before it applied to the string as a whole.
> Are we okay with that change?  (I've not yet looked to see if it's
> documented anywhere that it works that way...)  It's kind of tossing
> some of the optimization intended by f8e5f156b overboard, since when
> a timeout is active we'll be doing timeout calculations for each
> statement in the string.

I looked around, and as far as I can tell, there is no detail at all
about this in our user-facing docs.  I think we should apply a doc
patch more or less like the attached.  This fails to provide a complete
spec of what the behavior used to be, but I don't much care to try to
document that 100% exactly.

Anyone have an objection to pushing ahead with this for HEAD only?

            regards, tom lane

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 886632f..26ef8ff 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7592,11 +7592,25 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </term>
       <listitem>
        <para>
-        Abort any statement that takes more than the specified duration
-        (defaults to milliseconds), starting from the time the command arrives at the server
-        from the client.  If <varname>log_min_error_statement</varname> is set to
-        <literal>ERROR</literal> or lower, the statement that timed out will also be
-        logged.  A value of zero (the default) turns this off.
+        Abort any statement that takes more than the specified duration.
+        If <varname>log_min_error_statement</varname> is set
+        to <literal>ERROR</literal> or lower, the statement that timed out
+        will also be logged.
+        If the value is specified as a plain number, it is measured in
+        milliseconds by default.
+        A value of zero (the default) disables the timeout.
+       </para>
+
+       <para>
+        The timeout is measured from the time a command arrives at the
+        server until it is completed by the server.  If multiple SQL
+        statements appear in a single simple-Query message, the timeout
+        is applied to each statement separately.
+        (<productname>PostgreSQL</productname> versions before 13 usually
+        treated the timeout as applying to the whole query string.)
+        In extended query protocol, the timeout starts running when any
+        query-related message (Parse, Bind, Execute, Describe) arrives, and
+        it is cancelled by completion of an Execute or Sync message.
        </para>

        <para>