.SH GENERAL BACKEND OPTIONS
Options in these entries only apply to the configuration of a single
-type of backend. All backends may support this class of options.
+type of backend. All backends may support this class of options, but
+currently none do.
The entry must be named
.B olcBackend=<databasetype>,cn=config
and must have the olcBackendConfig objectClass.
.BR hdb ,
.BR ldap ,
.BR ldif ,
+.BR mdb ,
.BR meta ,
.BR monitor ,
+.BR ndb ,
.BR null ,
.BR passwd ,
.BR perl ,
.BR shell ,
or
.BR sql .
-At present, no backend implements any options of this type.
+At present, no backend implements any options of this type, so this
+entry should not be used.
.SH DATABASE OPTIONS
Database options are set in entries named
backend,
using less space and requiring less work to create, delete, and rename
entries. It is also one of the few backends to support subtree renames.
-.BR
.TP
.B ldap
This backend acts as a proxy to forward incoming requests to another
Its usage should be limited to very simple databases, where performance
is not a requirement. This backend also supports subtree renames.
.TP
+.B mdb
+This will soon be the recommended primary backend, superseding
+.BR hdb .
+This backend uses OpenLDAP's own MDB transactional database
+library. It is extremely compact and extremely efficient, delivering
+much higher performance than the Berkeley DB backends while using
+significantly less memory. Also, unlike Berkeley DB, MDB is crash proof,
+and requires no special tuning or maintenance.
+This backend also supports subtree renames.
+.TP
.B meta
This backend performs basic LDAP proxying with respect to a set of
remote LDAP servers. It is an enhancement of the
.B ndb
This backend is experimental.
It uses the transactional database interface of the MySQL Cluster Engine
-(NDB) to store data.
+(NDB) to store data. Note that Oracle, which now owns MySQL, has withdrawn
+support for NDB and this backend is unlikely to be developed any further.
.TP
.B null
Operations in this backend succeed but do nothing.
.BR slapd\-hdb (5),
.BR slapd\-ldap (5),
.BR slapd\-ldif (5),
+.BR slapd\-mdb (5),
.BR slapd\-meta (5),
.BR slapd\-monitor (5),
+.BR slapd\-ndb (5),
.BR slapd\-null (5),
.BR slapd\-passwd (5),
.BR slapd\-perl (5),