On 9/10/07, Heikki Linnakangas <[EMAIL PROTECTED]> wrote:
> Oh, one more thing occured to me. Without HOT, we not only mark index
> tuples pointing to dead tuples as killed, we remove them altogether if
> the index page gets full. If you modify the test case so that after
> doing the updates, you insert a bunch of tuples with a different key to
> fill the index page, you should see CVS HEAD winning HOT without pruning
> hands down.
Um. I am not sure I follow that. With HOT even if the HOT chain is long,
there is still just one index entry for the entire chain. So I don't see
why CVS HEAD would do better than HOT in the above case. Net-net
there will be equal number of index keys after the inserts.