Re: HOT for PostgreSQL 8.3

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