tunning search with less tha filter

Hi

i have to found entry with this filter in my ldap :

(&(statusprefix=free)(datefinjachere<=20110926))

i defined the datefinjachere attribut like this

attributetype ( 1.3.6.1.4.1.11594.1.2.5.1.7 NAME 'datefinjachere' DESC 'datefinjachere' EQUALITY numericStringMatch SUBSTR numericStringSubstringsMatch ORDERING numericStringOrderingMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.36{8} SINGLE-VALUE )

and i declare in my slapd.conf :

index datefinjachere eq index statusprefix eq

in the base where i search there is 1024 entry which corresponding or not at the filter

a search take 200 millisecondes for the moment, could someone tell me if there is some tunning configuration for better performances ?

i see when i log with debug

Sep 26 17:53:09 olivier slapd[3402]: => bdb_presence_candidates (datefinjachere) Sep 26 17:53:09 olivier slapd[3402]: <= bdb_presence_candidates: (datefinjachere) not indexed

perhaps i have to put index datefinjachere pres,eq in my conf ?

my *.bdb file take 2G on the disk and i declare 500M of cache berkeley in my myconf

bdb4.8 openldap 2.4.23

in advance, thank you for your time

Regards,

Olivier