Re: statement_timeout affects query results fetching?

Shay Rojansky <roji(at)roji(dot)org> writes:
> Hi everyone, I'm seeing some strange behavior and wanted to confirm it.
> When executing a query that selects a long result set, if the code
> processing the results takes its time (i.e.g more than statement_timeout),
> a timeout occurs. My expectation was that statement_timeout only affects
> query *processing*, and does not cover the frontend actually processing the
> result.

Are you using a cursor, or something like that?

libpq ordinarily absorbs the result set as fast as possible and then hands
it back to the application as one blob; the time subsequently spent by the
application looking at the blob doesn't count against statement_timeout.

As Robert says, statement_timeout *does* include time spent sending the
result set to the client, and we're not going to change that, because it
would be too hard to disentangle calculation from I/O. So if the client
isn't prompt about absorbing all the data then you have to factor that
into your setting. But it would be a slightly unusual usage pattern
AFAIK.

regards, tom lane