Problem to star openldap after configure DB_CONFIG file

["Eudes LEDUCQ" <LEDUCQ@hec.fr>]

Hi,
 
as i said in my preceding message, i have created a DB_CONFIG file for
my berkeley data base, after read the documentation . 
but i have this error:
 
backend_startup: starting "dc=ghec,dc=fr"
bdb_db_open: dbenv_open(/usr/local/openLdap2.2.28/var/openldap-data)
bdb(dc=ghec,dc=fr): unrecognized name-value pair: txn_checkpoint
bdb_db_open: dbenv_open failed: Invalid argument (22)
backend_startup: bi_db_open failed! (22)
slapd shutdown: initiated
====> bdb_cache_release_all
bdb(dc=ghec,dc=fr): DB_ENV->lock_id_free interface requires an
environment configured for the locking subsystem
slapd shutdown: freeing system resources.
bdb(dc=ghec,dc=fr): txn_checkpoint interface requires an environment
configured for the transaction subsystem
bdb_db_destroy: txn_checkpoint failed: Invalid argument (22)
slapd stopped.
connections_destroy: nothing to destroy.
 
My DB_CONFIG file:
 
# DB_CONFIG FILE
# The Berkeley Database backend retrieves most of its configuration and
tuning options from the DB_CONFIG file.
# This file should be placed in the same directory as specified by the
directory configuration option in the slapd.conf file.
 
#specifies a directory to search for database files
set_data_dir /usr/local/openLdap2.2.28/var/openldap-data
 
# Lockdetect directive
set_lk_detect DB_LOCK_DEFAULT
 
# Set database flags.
# specify that the database does not need to be updated
# immediately with any in-memory recard
set_flags DB_TXN_NOSYNC
 
# Set log values.
set_lg_max 5242880
set_lg_dir /usr/local/openLdap2.2.28/log
 
# Set temporary file creation directory.
set_tmp_dir /tmp
 
# Set the database in memory cache size.
# number of entry that the ldap backend will maintain im memory
set_cachesize 0 5242880 1
 
# Defines the time between checkpoint operation in BDB
txn_checkpoint 128 15 0


is some one can help me ?
 
thx.