Re: ldbm database usage

[dboreham@netscape.com (David Boreham)]

"MCGARRAHAN, KENNETH L (SWBT)" wrote:

> Though our use of OpenLDAP might be atypical, our LDAP server might be hit
> with something on the order of 6000 database additions and deletions (~3000
> each) per day. It appears that the resultant id2entry.?dbm file might be
> growing in size over time, even if the total number of entries served by the
> database is fairly constant (currently at 5000 entries).
> 
> It is unclear to me whether an ldbm back-end should/must be rebuilt
> periodically to reclaim index and/or data space.  Anyone with first hand
> experience? Care to share your knowledge?

The files should exhibit "high watermark" behavior.

That is, when new data is added, space taken up
by deleted entries will be used until there's no
more left. Then the file is extended. So the files
will grow to reflect the maximum amount of data
which resided in the server at any point in the past.
Files can never be shrunk, unless they're deleted
and recreated.

In your scenario, where entries are being 
added and deleted such that the total content
is relatively constant, the size of the files
should not grow without constraint*.

--
*Actually the secondary index files probably
will grow unless open-ldap now deletes index keys.
The primary index (id2entry) should not grow
unbounded.