Re: Timing of 'SELECT 1'

Merlin Moncure wrote:
> Bruce Momjian wrote:
> > I am timing small queries, and found that a PREPARE/EXECUTE of "SELECT
> > 1" takes about 1.2ms on my machine. A normal SELECT doesn't take much
> > longer, so I am wondering why a simpler query isn't faster.
> >
> > Looking at log_executor_stats, I see the following. Execute shows
> > nothing taking much time, mostly < .2ms, but the total seems high. I
> > wonder if one of our standard query start/stop functions is taking too
> > long and can be optimized.
>
> There seems to be a 'PostgreSQL ping' time of about 1-2 ms in best case
> conditions which limits the amount of queries you can fire off in 1
> second, no matter how simple. In certain rare cases this is something
> of a bottleneck. In my personal case it would be nice to see that time
> lower because converted COBOL applications tend to generate a lot of
> 'simple' queries.

Yes, most of that might be network time. I am using log_duration, which
I think just tests backend time, not network transfer time, but I might
be wrong. I want to look into this as it seems no one knows the answer.

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