Antw: Re: Q: index for operational attributes?

["Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de>]

>>> Michael Ströder <michael@stroeder.com> schrieb am 06.07.2017 um 14:29 in
Nachricht <55cd37d3-e407-877e-01be-096f9f7aacae@stroeder.com>:
> Ulrich Windl wrote:
>> Should I really add an index for modifyTimestamp? I got "slapd[4021]: <=
>> bdb_inequality_candidates: (modifyTimestamp) not indexed!" (No discussions

> on using
>> BDB, please!)
> 
> The pure log message does not say much. It depends on the real filters used

> whether you
> should index an attribute or not.
> Hint: You can make *search* performance worse with more indexes.

Actually the accesslog database wanted that index, while no queries (not that
I knew) were made on the accesslog database. So any access to it would be some
change operation in the main database (that's how accesslog is configures: only
log changes). So I don't know the filter.

It may be interesting that I had this configuration for more than a year now,
and those messages started to pop up only recently (a month ago or so). The
reqMod (largest file) has just about 51 MB in size, and reqStart has about
200kB in size....

At least those messages are gone after having added the index.

Regards,
Ulrich

> 
> Ciao, Michael.
> 
> P.S.: The log message is not helpful and e.g. with my Æ-DIR it's itself a 
> performance hog
> (see ITS#7796)