Re: db_stat and back-bdb index question

[Adam Tauno Williams <adam@morrison-ind.com>]

> > http://www.openldap.org/faq/data/cache/1075.html contains the paragraph
> > "Unlike the B-trees, where you only need to touch one data page to find
> > an entry of interest, doing an index lookup generally touches multiple
> > keys, and the point of a hash structure is that the keys are evenly
> > distributed across the data space. That means there's no convenient
> > compact subset of the database that you can keep in the cache to insure
> > quick operation, you can pretty much expect references to be scattered
> > across the whole thing. My strategy here would be to provide enough cache
> > for at least 50% of all of the hash data. (Number of hash buckets +
> > number of overflow pages + number of duplicate pages) * page size / 2."
> > Now I'm trying to match the phrases in that formulat to the output of
> > db_stat -d (?) resulting from looking at an index file.
> > Is -
> > Number of hash buckets = "Number of tree internal pages."
> > Numer of overflow pages = "Number of tree overflow pages."
> > Number of duplicate pages = "Number of tree duplicate pages."
> > Page Size = "Underlying database page size."
> > - correct?  Or should I use some other parametet to db_stat when looking
> > at these indexes (back-bdb)?
> > Is this information correct for back-hdb as well?
> What version of OpenLDAP are you using?
> OpenLDAP moved to using B-trees with the OpenLDAP 2.2 release.

2.2.24; So is there still a formula to calculate an equivalent value in 2.2.x?