Re: [martin@bugs.unl.edu.ar: BUG in logs] - Mailing list pgsql-bugs

I have now realized another complexity.  It is only _syntax_ errors that
are not logged via log_statement, not queries that generate other errors
during execution.  I have updated the documentation to mention "syntax
error", but it does make log_min_error_statement sub-optimal because if
log_min_error_statement and log_statement are both on, you get two lines
for the same query of the query generates a non-syntax error.  Yuck, but
I can see no better solution.

---------------------------------------------------------------------------

pgman wrote:
>
> I have looked at this behavior, which indeed is new for 8.1.  The change
> was caused by code I think I did to improve the behavior of
> log_statement, specifically streamlining how we check for the type of
> command.
>
> In looking at reverting to the 8.0 behavior of logging error commands
> with 'all', I see it is going to be hard to do, specifically since we
> added behavior of logging the PREPARE query when EXECUTE is sent.  I
> don't think we want to lose that feature, and to have it we have to
> first parse the statement, with possible exit on error.
>
> What I have done is to document that errors are not output by
> log_statement, and added as suggestion to use log_min_error_statement
> for this purpose.  I also fixed the code so the first EXECUTE has it's
> prepare, rather than the last which is what was in the current code.
>
> I also removed the "protocol" prefix from the PREPARE output, because in
> fact both protocol and SQL-level prepares can be executed by SQL
> EXECUTE.
>
> Patch attached.  I have backpatched this to 8.1.X.
>
> ---------------------------------------------------------------------------
>
> Martin Marques wrote:
> >
> > OK, you're right about the log_min_error_statement value, but this behaviour has changed from 8.0. In earlier
versionsERROR statements did get logged if log_statment was set to all or in 7.4, set to "on" DMaybe I missed something
inthe changelog of 8.1? 
> >
> > On Tue, 11 Apr 2006 23:51:51 +0200, "Guillaume Smet" <guillaume.smet@gmail.com> wrote:
> > >> From: Martin Marques <martin@bugs.unl.edu.ar>
> > >> I encountered a rare BUG in the way PG is logging. Let me first enlight
> > > with some configuration I have and PG version:
> > >
> > > Perhaps I'm missing something but I think it's not a bug but a
> > > configuration problem.
> > >
> > >>  log_min_error_statement    | panic
> > >
> > > If you set this one to error instead of panic, you will have your
> > > failed statements logged.
> > >
> > >>  log_statement              | all
> > >
> > > This one only logs successful queries so it's normal you don't have
> > > the statement in the log file if it fails.
> > >
> > > Regards,
> > >
> > >
> > --
> > ---------------------------------------------------------
> > Lic. Mart?n Marqu?s         |   SELECT 'mmarques' ||
> > Centro de Telem?tica        |       '@' || 'unl.edu.ar';
> > Universidad Nacional        |   DBA, Programador,
> >     del Litoral             |   Administrador
> > ---------------------------------------------------------
> >
> >
> >
> > ---------------------------(end of broadcast)---------------------------
> > TIP 9: In versions below 8.0, the planner will ignore your desire to
> >        choose an index scan if your joining column's datatypes do not
> >        match
> >
>
> --
>   Bruce Momjian   http://candle.pha.pa.us
>   EnterpriseDB    http://www.enterprisedb.com
>
>   + If your life is a hard drive, Christ can be your backup. +

> Index: doc/src/sgml/config.sgml
> ===================================================================
> RCS file: /cvsroot/pgsql/doc/src/sgml/config.sgml,v
> retrieving revision 1.52
> diff -c -c -r1.52 config.sgml
> *** doc/src/sgml/config.sgml    10 Mar 2006 19:10:47 -0000    1.52
> --- doc/src/sgml/config.sgml    18 Apr 2006 00:35:12 -0000
> ***************
> *** 2758,2766 ****
>          <note>
>           <para>
>            The <command>EXECUTE</command> statement is not considered a
> !          <literal>ddl</> or <literal>mod</> statement.  When it is logged,
> !          only the name of the prepared statement is reported, not the
> !          actual prepared statement.
>           </para>
>
>           <para>
> --- 2758,2767 ----
>          <note>
>           <para>
>            The <command>EXECUTE</command> statement is not considered a
> !          <literal>ddl</> or <literal>mod</> statement.  Statements that
> !          generate errors are not logged.  Set
> !          <varname>log_min_error_statement</> to <literal>error</> to
> !          log such statements.
>           </para>
>
>           <para>
> Index: src/backend/tcop/postgres.c
> ===================================================================
> RCS file: /cvsroot/pgsql/src/backend/tcop/postgres.c,v
> retrieving revision 1.483
> diff -c -c -r1.483 postgres.c
> *** src/backend/tcop/postgres.c    4 Apr 2006 19:35:35 -0000    1.483
> --- src/backend/tcop/postgres.c    18 Apr 2006 00:35:21 -0000
> ***************
> *** 586,604 ****
>
>           /*
>            * For the first EXECUTE we find, record the client statement used by
> !          * the PREPARE.
>            */
>           if (IsA(parsetree, ExecuteStmt))
>           {
>               ExecuteStmt *stmt = (ExecuteStmt *) parsetree;
>               PreparedStatement *entry;
>
> !             if ((entry = FetchPreparedStatement(stmt->name, false)) != NULL &&
>                   entry->query_string)
>               {
>                   *prepare_string = palloc(strlen(entry->query_string) +
> !                                       strlen("  [protocol PREPARE:  %s]") - 1);
> !                 sprintf(*prepare_string, "  [protocol PREPARE:  %s]",
>                           entry->query_string);
>               }
>           }
> --- 586,606 ----
>
>           /*
>            * For the first EXECUTE we find, record the client statement used by
> !          * the PREPARE.  PREPARE doesn't save the parse tree so we have no
> !          * way to conditionally output based on the type of query prepared.
>            */
>           if (IsA(parsetree, ExecuteStmt))
>           {
>               ExecuteStmt *stmt = (ExecuteStmt *) parsetree;
>               PreparedStatement *entry;
>
> !             if (*prepare_string == NULL &&
> !                 (entry = FetchPreparedStatement(stmt->name, false)) != NULL &&
>                   entry->query_string)
>               {
>                   *prepare_string = palloc(strlen(entry->query_string) +
> !                                       strlen("  [PREPARE:  %s]") - 2 + 1);
> !                 sprintf(*prepare_string, "  [PREPARE:  %s]",
>                           entry->query_string);
>               }
>           }

--
  Bruce Momjian   http://candle.pha.pa.us
  EnterpriseDB    http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +