Optimization help

What can I do to maximize the performance of my setup? System has 16gb of ram.

OpenLDAP 2.4.19-15

Import LDIF is 4,611,156 bytes. Backend is BDB.

du -c -h *.bdb

6.5M cn.bdb 8.0K displayName.bdb 1.9M dn2id.bdb 3.3M givenName.bdb 17M id2entry.bdb 5.6M mail.bdb 740K objectClass.bdb 7.5M ou.bdb 3.2M sn.bdb 3.4M uid.bdb 8.0K uidNumber.bdb 48M total

Portion of slapd.conf:

database bdb checkpoint 1024 15

##threads 8 cachesize 100000 idlcachesize 300000 ***no dncachesize (default infinite)

Current DB_CONFIG:

# one 0.25 GB cache ##set_cachesize 0 268435456 1 set_cachesize 1 0 1

# Data Directory #set_data_dir db

# Transaction Log settings set_lg_regionmax 262144 set_lg_bsize 2097152 #set_lg_dir logs