Simon Riggs wrote:
On Fri, 2007-02-09 at 13:39 +0000, Heikki Linnakangas wrote:
Tom Lane wrote:
ISTM we could fix that by extending the index VACUUM interface to
include two concepts: aside from "remove these TIDs when you find them",
there could be "replace these TIDs with those TIDs when you find them".
This would allow pointer-swinging to one of the child tuples, after
which the old root could be removed.
Implementing the "replace these TIDs" operation atomically would be simple, except for the new bitmap index am. It should be possible there as well, but if the old and new tid happen to be on a different bitmap page, it requires some care to avoid deadlocks.

Grouped Item Indexes cope with this easily also, yes?

Yes, as long as the old and the new tid point to the same page.

--
  Heikki Linnakangas
  EnterpriseDB   http://www.enterprisedb.com

---------------------------(end of broadcast)---------------------------
TIP 3: Have you checked our extensive FAQ?

              http://www.postgresql.org/docs/faq

Reply via email to