On 9/11/07, Bruce Momjian <bruce@momjian.us> wrote:
Right. My point is that pruning only modifies item pointers. It does
not change the actual heap tuples. In the quote above, how is Heikki's
"quick pruning" different from the pruning you are describing?
I think the only difference is that the quick pruning does not mark
intermediate tuples ~LP_USED and hence we may avoid WAL logging.
Btw, I am not too enthusiastic about quick pruning because it leaves
behind dead heap-only tuples which are not reachable from any root
heap tuples. Not that we can't handle them, but I am worried about
making such changes right now unless we are sure about the benefits.
We can always tune and tweak in 8.4
Thanks,
Pavan
--
Pavan Deolasee
EnterpriseDB
http://www.enterprisedb.com
