Re: Timing of 'SELECT 1'

Merlin Moncure kirjutas K, 10.03.2004 kell 17:00:
> 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.

Have you checked if this is a per-backend or per-connection limit?  

> 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.
> 
> Merlin
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 5: Have you checked our extensive FAQ?
> 
>                http://www.postgresql.org/docs/faqs/FAQ.html