Re: Timing of 'SELECT 1'

Bruce Momjian wrote:

>>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.
>
>
>
That's easy to verify with standard ping. In my switched 100MBit
network, roundtrip for small packets is about 0.2 ms, and 0.5ms for 1kb
packets. How about context switch latency?

Regards,
Andreas