ITS#7725 add nordahead envflag

[openldap] / doc / man / man5 / slapd-mdb.5

diff --git a/doc/man/man5/slapd-mdb.5 b/doc/man/man5/slapd-mdb.5
index 8a35b401cdf33ca2b09f51bd9707544544121fa9..180dd521af611cd318a7f745a5e1e37c1a78888a 100644 (file)
--- a/doc/man/man5/slapd-mdb.5
+++ b/doc/man/man5/slapd-mdb.5
@@ -1,5 +1,5 @@
 .TH SLAPD-MDB 5 "RELEASEDATE" "OpenLDAP LDVERSION"
-.\" Copyright 2011-2012 The OpenLDAP Foundation All Rights Reserved.
+.\" Copyright 2011-2013 The OpenLDAP Foundation All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
 .\" $OpenLDAP$
 .SH NAME
@@ -9,7 +9,7 @@ slapd\-mdb \- Memory-Mapped DB backend to slapd
 .SH DESCRIPTION
 The \fBmdb\fP backend to
 .BR slapd (8)
-uses OpenLDAP's own Memory-Mapped DB (MDB) library to store data.
+uses OpenLDAP's Lightning Memory-Mapped DB (LMDB) library to store data.
 It relies completely on the underlying operating system for memory
 management and does no caching of its own.
 .LP
@@ -48,14 +48,14 @@ By default, a full data flush/sync is performed when each
 transaction is committed.
 .TP
 .BI directory \ <directory>
-Specify the directory where the MDB files containing this database and
+Specify the directory where the LMDB files containing this database and
 associated indexes live.
 A separate directory must be specified for each database.
 The default is
 .BR LOCALSTATEDIR/openldap\-data .
 .TP
-\fBenvflags \fR{\fBnosync\fR,\fBnometasync\fR,\fBwritemap\fR,\fBmapasync\fR}
-Specify flags for finer-grained control of the MDB library's operation.
+\fBenvflags \fR{\fBnosync\fR,\fBnometasync\fR,\fBwritemap\fR,\fBmapasync\fR,\fBnordahead\fR}
+Specify flags for finer-grained control of the LMDB library's operation.
 .RS
 .TP
 .B nosync
@@ -94,6 +94,14 @@ has not been set. It also has no effect if
 .I nosync
 is set.
 .RE
+.RS
+.TP
+.B nordahead
+Turn off file readahead. Usually the OS performs readahead on every read
+request. This usually boosts read performance but can be harmful to
+random access read performance if the system's memory is full and the DB
+is larger than RAM. This option is not implemented on Windows.
+.RE
 
 .TP
 \fBindex \fR{\fI<attrlist>\fR|\fBdefault\fR} [\fBpres\fR,\fBeq\fR,\fBapprox\fR,\fBsub\fR,\fI<special>\fR]
@@ -186,7 +194,7 @@ configuration file
 .BR slapadd (8),
 .BR slapcat (8),
 .BR slapindex (8),
-OpenLDAP MDB documentation.
+OpenLDAP LMDB documentation.
 .SH ACKNOWLEDGEMENTS
 .so ../Project
 Written by Howard Chu.