Re: fix log_min_duration_statement logic error

Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > Tom Lane wrote:
> >> I would prefer to see the log entries look like
> >>
> >> LOG: query: select * from pg_class;
> >> LOG: duration: nn.nnn msec
>
> > The problem with two lines is that another log message could get between
> > them.
>
> That was true already with log_statement and log_duration as separate
> operations.  People use log_pid to deal with it.

Attached are some emails I sent while we were discussing this feature in
March.

The idea was for the parameter to show query and duration --- a
combination that is asked for frequently and easily grep'ed, unlike
joining on pid, which because of pid wrap-around, isn't even fool-proof.

One thing that isn't implemented in current CVS is to allow 0 to always
print the duration and query (-1 disables it and is the default).  I can
see that being _very_ valuable, and used enough to warrant the fact that
it isn't orthoginal (we already have log_statement).  The reason we
needed to do it this way was so we could print the statement _after_ it
completes so we could include the duration.

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