"Simon Riggs" <[EMAIL PROTECTED]> writes:
> That was understood; in the above example I agree you need to flush. If
> you don't pass a truncation point, you don't need to flush whether or
> not you actually truncate. So we don't need to flush *every* time,
OK, but does that actually do much of anything for your performance
complaint? Just after GlobalXmin has passed a truncation point, *every*
vacuum the system does will start performing a flush-n-fsync, which
seems like exactly what you didn't like. If the syncs were spread out
in time for different rels then maybe this idea would help, but AFAICS
they won't be.
regards, tom lane
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
