Re: limiting hint bit I/O

Robert Haas <robertmhaas@gmail.com> writes:
> On Fri, Jan 14, 2011 at 1:42 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Um, yeah, I think you're having a problem keeping all the ideas straight
>> ;-). The argument about forensics has to do with how soon we're willing
>> to freeze tuples, ie replace the XID with a constant. Not about hint
>> bits.

> Those things are related, though.  Freezing sooner could be viewed as
> an alternative to hint bits.

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.

			regards, tom lane