my searchs doesn't use indexes

["Isaac Cruz Ballesteros" <icruz@sgi.es>]

Hello,

I have OpenLdap 2.0.23 installed using GDBM 1.8.0 in a Solaris 8 machine (sparc).
I have installed 6000000 entries under ou=subscriber, with attributes "msisdn" and
"tac"; and 4647 entries under ou=devices, with lots of attributes one of which is
"tac". Basically, I have a msisdn, make a search in ou=subscriber to obtain the
tac, and make a search in ou=devices with tac=.... as a filter.

the indexes are: msisdn,tac pres,eq

The problem is, the first search in subscriber is immediate, but the second search
under devices is worth about a minute the first time.
I have made a test with debug at 805, starting slapd, and run the command:
ldapsearch -b "ou=devices" tac=35067323

and in the log I can see it opens tac.gdbm and obtain 4648 candidates, so it
doesn't use the index to obtain only one candidate, and begins searching one by
one. The next search under this branch is almost immediate because all the entries
are in cache.

Anyone have a suggestion? I cannot use it in a production environment with this
problem. Could it be a bug in GDBM? I have a test machine with the same
configuration, and it works correctly.

Thanks in advance,
Isaac