Re: [PERFORM] COUNT(*) again (was Re: [HACKERS] Index/Function organized table layout)
Bruce Momjian <[EMAIL PROTECTED]> writes: > Tom Lane wrote: >> I think that's not happening, conditionally or otherwise. The atomicity >> problems alone are sufficient reason why not, even before you look at >> the performance issues. > What are the atomicity problems of adding a create/expire xid to the > index tuples? You can't update a tuple's status in just one place ... you have to update the copies in the indexes too. regards, tom lane ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [PERFORM] COUNT(*) again (was Re: [HACKERS] Index/Function organized table layout)
Hannu Krosing <[EMAIL PROTECTED]> writes: > The point I was trying to make was that faster count(*)'s is just a side > effect. If we could (conditionally) keep visibility info in indexes, I think that's not happening, conditionally or otherwise. The atomicity problems alone are sufficient reason why not, even before you look at the performance issues. regards, tom lane ---(end of broadcast)--- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
