Re: Sync vs Flush

Jaka Jančar <jaka@kubje.org> writes:
> What is a common situation for using Flush instead of Sync?
> When would you need and wait for the output, get an error, yet still
> proceed to send further messages that you would want the server to ignore?

The only case I can think of offhand is bursting some time-consuming
queries to the server, that is sending this all at once:

   Execute, Flush, Execute, Flush, Execute, Flush, Execute, Sync

This presumes that, if an earlier query fails, you want the rest
to be abandoned; else you'd use Syncs instead.  But if you leave
out the Flushes then you won't see the tail end of (or indeed
maybe none of) the output of an earlier query until a later query
fills the server's output buffer.  So if you're hoping to overlap
the client's processing with the server's you want the extra flushes.

                        regards, tom lane