Re: Dead Space Map version 2

Heikki Linnakangas <heikki@enterprisedb.com> writes:
> Tom Lane wrote:
>> I'd be happier if the DSM content could be
>> treated as just a hint.

> If we don't have a frozen state, we can't use the DSM to implement 
> index-only scans.

To implement index-only scans, the DSM would have to be expected to
provide 100% reliable coverage, which will increase its cost and
complexity by orders of magnitude.  If you insist on that, I will bet
you lunch at a fine restaurant that it doesn't make it into 8.3.
        regards, tom lane