Re: HOT line pointer bloat and PageRepairFragmentation

On 9/13/07, Zeugswetter Andreas ADI SD <Andreas(dot)Zeugswetter(at)s-itsolutions(dot)at>
wrote:
>
>
> > CREATE TABLE test (a int, b char(200));
> > CREATE UNIQUE INDEX testindx ON test(a);
> > INSERT INTO test VALUES (1, 'foo');
> >
> > Now, if we repeatedly update the tuple so that each update is a
> > COLD update, we would bloat the page with redirect-dead line pointers.
>
> Um, sorry for not understanding, but why would a COLD update produce a
> redirect-dead line pointer (and not two LP_NORMAL ones) ?
>
>
The COLD updated (old) tuple would be pruned to dead line pointer
once the tuple becomes DEAD. Normally that would let us reuse the
tuple storage for other purposes. We do the same for DELETEd tuples.

Thanks,
Pavan

--
Pavan Deolasee
EnterpriseDB http://www.enterprisedb.com