Re: Exec statement logging

Simon Riggs wrote:
> Following patch is a minor addition to postgres.c that allows the two
> existing statement logging techniques to work with V3 exec. This then
> allows statement logging with PostgreSQL 8.0+ for JDBC and other V3
> connection types.

Good.

> The rationale of this patch is to add functionality without modifying
> existing behaviour. There is expected to be some difficulty with
> log_statement producing a log line at both parse and exec, but some may
> find that useful. Since there are two ways of producing statement
> logging with duration times, setting log_min_duration_statement=0 will
> avoid the logging of statements for both parse and exec. For many this
> method is already the preferred way of logging statement performance
> stats.

I don't understand what you are saying above. How is the logging
different from what we currently have in terms of the GUC variables?

> There is no attempt to log parameters, since these are not often
> required for performance analysis.

Makes sense.

> The enclosed patch has been tested against cvstip.
>
> I also see this as a backpatch onto 8.0, since it prevents statements
> from being logged as described in the manual and prevents effective
> performance tuning. It has not been tested against 8.0.2, though was
> originally written against 8.0.1 and is believed to apply cleanly.

Unlikely for 8.0.X as current behavior is not a bug nor has it been
complained about alot.

> Some code has been duplicated with this patch; refactoring and cleanup
> can be performed should anybody desire it.

Yes, is it worth factoring it out? I am thinking not.

> The patch was produced quickly to assist tuning efforts during
> Scalability & Performance benchmarking of PostgreSQL 8.0 carried out at
> Unisys Corporation's Mission Viejo engineering laboratory. The
> development was sponsored by Unisys Corporation and the patch has now
> been donated to the PostgreSQL community under the standard
> PostgreSQL/BSD licence. Approval for release of this code has been given
> in writing to me by the Director, Open Runtime Products, Unisys on April
> 8, 2005.

Amazing something in writing was required for this. Was this their
idea, or yours, or based on their previous litigation over the "GIF"
patent?

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