diff -uPpr tdb-1.2.9/common/io.c tdb-1.2.9.fix/common/io.c
--- tdb-1.2.9/common/io.c	2010-10-13 21:08:49.000000000 -0400
+++ tdb-1.2.9.fix/common/io.c	2011-04-05 11:47:14.761341926 -0400
@@ -299,7 +299,7 @@ static int tdb_expand_file(struct tdb_co
 int tdb_expand(struct tdb_context *tdb, tdb_off_t size)
 {
 	struct tdb_record rec;
-	tdb_off_t offset, new_size;	
+	tdb_off_t offset, new_size, top_size;
 
 	if (tdb_lock(tdb, -1, F_WRLCK) == -1) {
 		TDB_LOG((tdb, TDB_DEBUG_ERROR, "lock failed in tdb_expand\n"));
@@ -309,10 +309,18 @@ int tdb_expand(struct tdb_context *tdb, 
 	/* must know about any previous expansions by another process */
 	tdb->methods->tdb_oob(tdb, tdb->map_size + 1, 1);
 
+	/* limit size in order to avoid using up huge amounts of memory for
+	 * in memory tdbs if an oddball huge record creeps in */
+	if (size > 100 * 1024) {
+		top_size = size * 2;
+	} else {
+		top_size = size * 100;
+	}
+
 	/* always make room for at least 100 more records, and at
-           least 25% more space. Round the database up to a multiple
-           of the page size */
-	new_size = MAX(tdb->map_size + size*100, tdb->map_size * 1.25);
+	   least 25% more space. Round the database up to a multiple
+	   of the page size */
+	new_size = MAX(tdb->map_size + top_size, tdb->map_size * 1.25);
 	size = TDB_ALIGN(new_size, tdb->page_size) - tdb->map_size;
 
 	if (!(tdb->flags & TDB_INTERNAL))