Re: Avoiding redundant fetches of btree index metapages

On Wed, 2006-04-26 at 12:53 -0400, Tom Lane wrote:
> > So we would be able to cache other items also?
>
> Only to the extent that you can guarantee a stale cache entry isn't a
> problem. We've already done the analysis involved for the existing
> metapage entries, but anything else would require more thought. (And
> more cache flush events.)

You mean performance tests! Will do.

Methinks that cache flushing is the key to performance for that idea.

> > For that case we'd save N block accesses to locate the rightmost leaf
> > page.
>
> Surely you mean log(N).

Depends what N is. I meant the level, not the number of rows.

--
Simon Riggs
EnterpriseDB http://www.enterprisedb.com/