diff --git a/man/mu-index.1 b/man/mu-index.1
index eaa2a640..fa3b914d 100644
--- a/man/mu-index.1
+++ b/man/mu-index.1
@@ -1,4 +1,4 @@
-.TH MU-INDEX 1 "November 2010" "User Manuals"
+.TH MU-INDEX 1 "January 2011" "User Manuals"
 
 .SH NAME 
 
@@ -10,11 +10,11 @@ mu index \- index e-mail messages stored in Maildirs
 
 .SH DESCRIPTION
 
-\fBmu index\fR is the \fBmu\fR sub-command for scanning the contents of
-Maildir directories and storing the results in a Xapian database which can
-then be searched using
+\fBmu index\fR is the \fBmu\fR command for scanning the contents of Maildir
+directories and storing the results in a Xapian database. The data can then be
+queried using
 .BR mu-find(1)
-\.
+\.	
 
 .B index
 understands Maildirs as defined by Daniel Bernstein for qmail(7). In addition,
@@ -34,17 +34,14 @@ with spam-messages.
 
 The first run of \fBmu index\fR may take a few minutes if you have a lot of
 mail (ten thousands of messages).  Fortunately, such a full scan needs to be
-done only once, after that it suffices to index the changes, which goes much
-faster. Also note that a substantial amount of the time goes to printing the
-progress information; if you turn that off (with \fB\-q\fR or
-\fB\-\-quiet\fR), it goes a lot faster. See the 'Note on performance' below
-for more information.
+done only once; after that it suffices to index the changes, which goes much
+faster. See the 'Note on performance' below for more information.
 
-The optional phase two of the indexing-process is the removal of messages from
-the database for which there is no longer a corresponding file in the
+The optional 'phase two' of the indexing-process is the removal of messages
+from the database for which there is no longer a corresponding file in the
 Maildir. If you do not want this, you can use \fB\-n\fR, \fB\-\-nocleanup\fR.
 
-When \fBmu index\fR catches on of the signals \fBSIGINT\fR, \fBSIGHUP\fR or
+When \fBmu index\fR catches one of the signals \fBSIGINT\fR, \fBSIGHUP\fR or
 \fBSIGTERM\fR (e.g,, when you press Ctrl-C during the indexing process), it
 tries to shutdown gracefully; it tries to save and commit data, and close the
 database etc. If it receives another signal (e.g,, when pressing Ctrl-C once
@@ -52,16 +49,14 @@ more), \fBmu index\fR will terminate immediately.
 
 .SH OPTIONS
 
-Note, some of the important options are described in the \fBmu(1)\fR man-page
-and not here, as they apply to multiple mu-commands.
+Note, some of the general options are described in the \fBmu(1)\fR man-page
+and not here, as they apply to multiple mu commands.
 
 .TP
 \fB\-m\fR, \fB\-\-maildir\fR=\fI<maildir>\fR
 starts searching at \fI<maildir>\fR. By default, \fBmu\fR uses whatever the
-\fBMAILDIR\fR environment variable is set to; if that is not set, it tries
-\fI~/Maildir\fR \. In either case, the path must be \fBabsolute\fR.
-
-Also please see the note on mixing sub-maildirs below.
+\fBMAILDIR\fR environment variable is set to; if it is not set, it tries
+\fI~/Maildir\fR. See the note on mixing sub-maildirs below.
 
 .TP
 \fB\-\-reindex\fR
@@ -83,23 +78,25 @@ messages (using \fB\-\-maildir\fR). For this reason, it is necessary to run
 format. \fBmu index\fR will issue a warning about this.
 
 .TP
-\fB\-\-autoupgrade\fR automatically use \fB\-y\fR, \fB\-\-empty\fR
+\fB\-\-autoupgrade\fR
+automatically use \fB\-y\fR, \fB\-\-empty\fR
 when \fBmu\fR notices that the database version is not up-to-date. This option
 is for use in cron scripts and the like, so they won't require any user
 interaction, even when mu introduces a new database version.
 
 .TP
+\fB\-\-xbatchsize\fR=\fI<batch size>\fR
+set the maximum number of messages to process in a single Xapian
+transaction. In practice, this option is only useful if you find that \fBmu\fR
+is running out of memory while indexing; in that case, you can set the batch
+size to (for example) 1000, which will reduce memory consumption, but also
+reduce performance.
 
 .B NOTE:
-It is not a good idea to run multiple instances of
-.B mu index
+It is generally not a good idea to run multiple instances of \fBmu index\fR
 concurrently. No data loss should occur, but one or more of the instances may
 experience errors due to database locks.
 
-Also note that, before indexing is completed, searches for messages may fail,
-even if they have already been indexed, as some of the esssential database
-information will only be written in batches during the indexing process.
-
 Furthermore, it is not recommended tot mix maildirs and sub-maildirs within
 the hierarchy in the same database; for example, it's better not to index both
 with \fB\-\-maildir\fR=~/MyMaildir and \fB\-\-maildir\fR=~/MyMaildir/foo, as
@@ -179,6 +176,4 @@ Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
 
 .SH "SEE ALSO"
 
-.BR maildir(5)
-.BR mu(1)
-.BR mu-find(1)
+.BR maildir(5) mu(1) mu-find(1)
diff --git a/src/mu-config.h b/src/mu-config.h
index 2d311749..38b8a154 100644
--- a/src/mu-config.h
+++ b/src/mu-config.h
@@ -27,10 +27,28 @@
 
 G_BEGIN_DECLS
 
+enum _MuConfigCmd {
+	MU_CONFIG_CMD_INDEX,
+	MU_CONFIG_CMD_FIND,
+	MU_CONFIG_CMD_CLEANUP,
+	MU_CONFIG_CMD_MKDIR,
+	MU_CONFIG_CMD_VIEW,
+	MU_CONFIG_CMD_EXTRACT,
+	MU_CONFIG_CMD_NONE,
+	
+	MU_CONFIG_CMD_UNKNOWN
+};
+typedef enum _MuConfigCmd MuConfigCmd;
+
+
+
 /* struct with all configuration options for mu; it will be filled
  * from the config file, and/or command line arguments */
 
 struct _MuConfigOptions {
+
+	MuConfigCmd      cmd;           /* the command, or MU_CONFIG_CMD_NONE */
+	const char       *cmdstr;       /* cmd string, for user info */
 	
 	/* general options */
 	gboolean	 quiet;         /* don't give any output */
@@ -47,6 +65,9 @@ struct _MuConfigOptions {
 	gboolean         rebuild;       /* empty the database before indexing */
 	gboolean         autoupgrade;   /* automatically upgrade db
 					 * when needed */
+	int		 xbatchsize;    /* batchsize for xapian commits, or 0 for default
+					 * */
+	
 	/* options for querying */
 	gboolean         xquery;        /* give the Xapian query instead of
 					   search results */
diff --git a/src/mu-index.c b/src/mu-index.c
index 01f757ad..d509fb1c 100644
--- a/src/mu-index.c
+++ b/src/mu-index.c
@@ -41,14 +41,14 @@ struct _MuIndex {
 };
 
 MuIndex* 
-mu_index_new (const char *xpath, GError **err)
+mu_index_new (const char *xpath, guint xbatchsize, GError **err)
 {
 	MuIndex *index;
 
 	g_return_val_if_fail (xpath, NULL);
 	
 	index = g_new0 (MuIndex, 1);				
-	index->_xapian = mu_store_new (xpath, err);
+	index->_xapian = mu_store_new (xpath, xbatchsize, err);
 	
 	if (!index->_xapian) {
 		g_warning ("%s: failed to open xapian store (%s)",
diff --git a/src/mu-index.h b/src/mu-index.h
index 86b86402..861ed004 100644
--- a/src/mu-index.h
+++ b/src/mu-index.h
@@ -51,7 +51,7 @@ typedef struct _MuIndexStats MuIndexStats;
  * 
  * @return a new MuIndex instance, or NULL in case of error
  */
-MuIndex* mu_index_new (const char* muhome, GError **err)
+MuIndex* mu_index_new (const char* muhome, guint batchsize, GError **err)
     G_GNUC_MALLOC G_GNUC_WARN_UNUSED_RESULT;
 
 
diff --git a/src/mu-store.cc b/src/mu-store.cc
index c53a82fc..2dfbb599 100644
--- a/src/mu-store.cc
+++ b/src/mu-store.cc
@@ -32,8 +32,8 @@
 #include "mu-str.h"
 #include "mu-msg-flags.h"
 
-/* number of new messages after which we commit to the database */
-#define MU_STORE_TRX_SIZE 6666
+/* by default, use transactions of 30000 messages */
+#define MU_STORE_DEFAULT_TRX_SIZE 30000
 
 /* http://article.gmane.org/gmane.comp.search.xapian.general/3656 */
 #define MU_STORE_MAX_TERM_LENGTH 240
@@ -47,6 +47,7 @@ struct _MuStore {
 	bool   _in_transaction;
 	int    _processed;
 	size_t _trx_size;
+	guint  _batchsize;  /* batch size of a xapian transaction */ 
 };
 
 
@@ -115,7 +116,7 @@ check_version (MuStore *store)
 }
 
 MuStore*
-mu_store_new  (const char* xpath, GError **err)
+mu_store_new  (const char* xpath, guint batchsize, GError **err)
 {
 	MuStore *store (0);
 	
@@ -131,14 +132,15 @@ mu_store_new  (const char* xpath, GError **err)
 		}
 
 		/* keep count of processed docs */
-		store->_trx_size = MU_STORE_TRX_SIZE; 
 		store->_in_transaction = false;
-		store->_processed = 0;
+		store->_processed      = 0;
+		store->_trx_size       = batchsize ? batchsize : MU_STORE_DEFAULT_TRX_SIZE;
 		
 		add_synonyms (store);
 		
-		MU_WRITE_LOG ("%s: opened %s", __FUNCTION__, xpath);
-
+		MU_WRITE_LOG ("%s: opened %s (batch size: %u)",
+			      __FUNCTION__, xpath, store->_trx_size);
+		
 		return store;
 
 	} MU_XAPIAN_CATCH_BLOCK_G_ERROR(err,MU_ERROR_XAPIAN);		
diff --git a/src/mu-store.h b/src/mu-store.h
index 9e2163a1..5f48112b 100644
--- a/src/mu-store.h
+++ b/src/mu-store.h
@@ -36,12 +36,13 @@ typedef struct _MuStore MuStore;
  * create a new Xapian store, a place to store documents
  * 
  * @param path the path to the database
-  * @param err to receive error info or NULL. err->code can be found in
+ * @param batchsize size of batch before committing
+ * @param err to receive error info or NULL. err->code can be found in
  * mu-error.h
  * 
  * @return a new MuStore object, or NULL in case of error
  */
-MuStore*    mu_store_new     (const char *path, GError **err)
+MuStore*    mu_store_new     (const char *path, guint batchsize, GError **err)
     G_GNUC_MALLOC G_GNUC_WARN_UNUSED_RESULT;
 
 
diff --git a/src/tests/test-mu-cmd.c b/src/tests/test-mu-cmd.c
index 62ac3fce..71062f7e 100644
--- a/src/tests/test-mu-cmd.c
+++ b/src/tests/test-mu-cmd.c
@@ -113,7 +113,7 @@ test_mu_index (void)
 	xpath = g_strdup_printf ("%s%c%s", muhome, G_DIR_SEPARATOR,
 				 "xapian");
 	
-	store = mu_store_new (xpath, NULL);
+	store = mu_store_new (xpath, 0, NULL);
 	g_assert (store);
 
 	g_assert_cmpuint (mu_store_count (store), ==, 4);	
diff --git a/src/tests/test-mu-store.c b/src/tests/test-mu-store.c
index 299e91e5..bf8c36b5 100644
--- a/src/tests/test-mu-store.c
+++ b/src/tests/test-mu-store.c
@@ -42,7 +42,7 @@ test_mu_store_new_destroy (void)
 	g_assert (tmpdir);
 
 	err = NULL;
-	store = mu_store_new (tmpdir, &err);	
+	store = mu_store_new (tmpdir, 12345, &err);	
 	g_assert (store);
 	g_assert (err == NULL);
 
@@ -68,7 +68,7 @@ test_mu_store_version (void)
 	g_assert (tmpdir);
 
 	err = NULL;
-	store = mu_store_new (tmpdir, &err);	
+	store = mu_store_new (tmpdir, 789, &err);	
 	g_assert (store);
 	g_assert (err == NULL);
 
@@ -94,7 +94,7 @@ test_mu_store_store_and_count (void)
 		tmpdir = test_mu_common_get_random_tmpdir();
 		g_assert (tmpdir);
 
-		store = mu_store_new (tmpdir, NULL);	
+		store = mu_store_new (tmpdir, 1, NULL);	
 		g_assert (store);
 		
 		g_assert_cmpuint (0,==,mu_store_count (store));
@@ -142,7 +142,7 @@ test_mu_store_store_remove_and_count (void)
 		tmpdir = test_mu_common_get_random_tmpdir();
 		g_assert (tmpdir);
 
-		store = mu_store_new (tmpdir, NULL);	
+		store = mu_store_new (tmpdir, 0, NULL);	
 		g_assert (store);
 		
 		g_assert_cmpuint (0,==,mu_store_count (store));