Re: directory performance on modifytimestamp and createtimestamp

[Hallvard B Furuseth <h.b.furuseth@usit.uio.no>]

Flack, Simon writes:
> Has anyone tried creating an index in openldap to speed-up inequality
> searches ( eg of the form modifyTimestamp>=20111025162408Z ) on the
> modifytimestamp or createtimestamp attributes ?
> 
> If so, what type of index did you create,

I haven't tried recently, but use an 'eq' index.  This also provides an
inequality index for certain syntaxes - timestamps, CSNs, and recently
integers, I don't remmeber what else.

> did openldap perform reads faster than with no index

An index gives faster non-base searches with such an filer, not faster
reads as such.  What an index does is narrow down the number of entries
in the search scope which slapd has to read and test with the filter.

> and did the presence of the index slow down
> writes to openldap appreciably ?

Each index does slow writes down a somewhat, in particular substring
indexes.  The question has raraly been relevant: We could go wild with
indexes and OpenLDAP would still be faster than we need.

-- 
Hallvard