.SH DESCRIPTION
The \fBbdb\fP backend to
.BR slapd (8)
-is the recommended primary backend for a normal
-.B slapd
-database.
-It uses the Oracle Berkeley DB (BDB) package to store data.
+uses the Oracle Berkeley DB (BDB) package to store data.
It makes extensive use of indexing and caching to speed data access.
.LP
-\fBhdb\fP is a variant of the \fBbdb\fP backend that uses a
-hierarchical database
-layout which supports subtree renames. It is otherwise identical to
-the \fBbdb\fP behavior, and all the same configuration options apply.
+\fBhdb\fP is the recommended primary database backend. It is a variant of
+the \fBbdb\fP backend that uses a hierarchical database layout which
+supports subtree renames. It is both more space-efficient and more
+execution-efficient than the \fBbdb\fP backend. It is otherwise identical
+to the \fBbdb\fP behavior, and all the same configuration options apply.
.LP
It is noted that these options are intended to complement
Berkeley DB configuration options set in the environment's
manual pages.
.TP
.B bdb
-This is the recommended primary backend for a normal slapd database.
-It takes care to configure it properly.
+This was the recommended primary backend through OpenLDAP 2.3, but it has
+since been superseded by the
+.BR hdb
+backend. It takes care to configure it properly.
It uses the transactional database interface of the Oracle Berkeley
DB (BDB) package to store data.
.TP
Domain Name System.
.TP
.B hdb
-This is a variant of the
+This is the recommended primary backend for a normal slapd database.
+.B hdb
+is a variant of the
.B bdb
backend that uses a hierarchical database
-layout. This layout stores entry DNs more efficiently than the
+layout.
+This layout stores entry DNs more efficiently than the
.B bdb
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