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Re: OpenLDAP performance vs. PostgreSQL



On Wednesday 15 March 2006 16:58, Peter Mogensen wrote:
> Hi,
>
> An often heard argument for LDAP is that it is optimized for many reads
> and only a few writes. ... And it seems intuitively reasonable that it
> should be faster than an RDBMS for such applications.
>
> Now... I have a lot of configuration data for many users, which I need
> to query very often and write very seldom. There's not many relational
> contraints in it, so I figured OpenLDAP would be better than PostgreSQL.
>
> But a quick test using Perl DBD::Pg and Net::LDAP shows me that this
> might not be the case. In short I tried to:
> 1 Insert 20000 simple objects with index on PK/DN
> 2 Query 20000 objects on the indexed attribute
> 3 Query 10000 objects on a non-indexed attribute
>
> The results was (in seconds):
>
> PostgreSQL (7.4.7):
>
> 1: 20
> 2: 10
> 3: 150
>
> OpenLDAP (2.2.23) (BDB-backend):
>
> 1: 185
> 2: 49
> 3:  -
>
>
> I didn't bother wait for the last run. ... I was probably way over 1000.
> Now it didn't surprise me that LDAP was slower for inserts, but it did
> surprise me that it was 5 times slower for lookups on an indexed attribute.

With single-bind many-queries, results of over 20 000 searches/second are 
possible (on indexed attributes) without too much tuning on reasonable (ie 
dual 3 GHz Xeon) hardware.

So, I suspect you have missed some tuning, most likely you have no DB_CONFIG 
file in your database directory, or it is inadequately tuned.

More information (ie slapd.conf extracts, log extracts, DB_CONFIG file etc) 
would help ...

Regards,
Buchan

-- 
Buchan Milne
ISP Systems Specialist
B.Eng,RHCE(803004789010797),LPIC-2(LPI000074592)

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