Re: TCP network cost

Tom Lane escribió:
> Linos <info@linos.es> writes:
>> Hello, i have been having a problem like this in debian machines and i have
>> discovered that (almost in my case), the problem only arises when i am using
>> "ssl = true" in postgresql.conf although i am using clear tcp connections to
>> localhost to perform my query, if i disable ssl in configuration my localhost
>> query times goes from 4200ms to 110ms,
>
> Does that number include connection startup overhead?  (If it doesn't,
> it'd be pretty strange.)  Ross's problem is not about startup overhead,
> unless I've misread him completely.
>
>             regards, tom lane

This difference it is from the runtime of the query, i get this with \timing
parameter in psql, it is from a table that have 300 small png (one for every row
in table) on a bytea column but the problem grows with any large result anyway,
i have attacted pcap files in general list but the differences are like this:

ssl enabled:
`psql -d database`: SELECT * FROM TABLE (110 ms with \timing)
`psql -d database -h localhost`: SELECT * FROM TABLE (4200 ms with \timing)

ssl disabled:
`psql -d database`: SELECT * FROM TABLE (110 ms with \timing)
`psql -d database -h localhost`: SELECT * FROM TABLE (120 ~ 130 ms with \timing)

Anyway i dont know if this apply to Ross problem but reading his post and after
see that he is using debian and have problem with speed on tcp localhost i
suppose that maybe have the same problem.

Regards,
Miguel Angel