Re: limiting hint bit I/O

Robert Haas <robertmhaas@gmail.com> writes:
> On Fri, Jan 14, 2011 at 2:09 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Freezing sooner isn't likely to reduce I/O compared to hint bits. �What
>> that does is create I/O that you *have* to execute ... both in the pages
>> themselves, and in WAL.

> It depends on which way you tilt your head - right now, we rewrite
> each table 3x - once to populate, once to hint, and once to freeze.
> If the table is doomed to survive long enough to go through all three
> of those, then freezing is better than hinting.  Of course, that's not
> always the case, but people keep complaining about the way this shakes
> out.

The people whose tables are mostly insert-only complain about it, but
that's not the majority of our userbase IMO.  We just happen to have a
couple of particularly vocal ones, like Berkus.
        regards, tom lane