diff --git a/src/calibre/library/__init__.py b/src/calibre/library/__init__.py
index 0f8e5e5496..8ff23c0a0a 100644
--- a/src/calibre/library/__init__.py
+++ b/src/calibre/library/__init__.py
@@ -6,3 +6,53 @@ def db(path=None):
     from calibre.library.database2 import LibraryDatabase2
     from calibre.utils.config import prefs
     return LibraryDatabase2(path if path else prefs['library_path'])
+
+
+def generate_test_db(library_path,
+        num_of_records=20000,
+        num_of_authors=6000,
+        num_of_tags=10000,
+        tag_length=7,
+        author_length=7,
+        title_length=10,
+        max_authors=10,
+        max_tags=10
+        ):
+    import random, string, os, sys, time
+
+    if not os.path.exists(library_path):
+        os.makedirs(library_path)
+
+    def randstr(length):
+        return ''.join(random.choice(string.letters) for i in
+                xrange(length))
+
+    all_tags = [randstr(tag_length) for j in xrange(num_of_tags)]
+    print 'Generated', num_of_tags, 'tags'
+    all_authors = [randstr(author_length) for j in xrange(num_of_authors)]
+    print 'Generated', num_of_authors, 'authors'
+    all_titles = [randstr(title_length) for j in xrange(num_of_records)]
+    print 'Generated', num_of_records, 'titles'
+
+    testdb = db(library_path)
+
+    print 'Creating', num_of_records, 'records...'
+
+    start = time.time()
+
+    for i, title in enumerate(all_titles):
+        print i+1,
+        sys.stdout.flush()
+        authors = random.randint(1, max_authors)
+        authors = [random.choice(all_authors) for i in xrange(authors)]
+        tags = random.randint(0, max_tags)
+        tags = [random.choice(all_tags) for i in xrange(tags)]
+        from calibre.ebooks.metadata.book.base import Metadata
+        mi = Metadata(title, authors)
+        mi.tags = tags
+        testdb.import_book(mi, [])
+
+    t = time.time() - start
+    print '\nGenerated', num_of_records, 'records in:', t, 'seconds'
+    print 'Time per record:', t/float(num_of_records)
+
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index 44e7449295..21a54a4dd6 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -2089,8 +2089,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
             mi.timestamp = utcnow()
         if mi.pubdate is None:
             mi.pubdate = utcnow()
-        self.set_metadata(id, mi, ignore_errors=True, commit=False)
-        self.conn.commit()
+        self.set_metadata(id, mi, ignore_errors=True, commit=True)
         if cover is not None:
             try:
                 self.set_cover(id, cover)
@@ -2130,8 +2129,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
                 mi.timestamp = utcnow()
             if mi.pubdate is None:
                 mi.pubdate = utcnow()
-            self.set_metadata(id, mi, commit=False)
-            self.conn.commit()
+            self.set_metadata(id, mi, commit=True, ignore_errors=True)
             npath = self.run_import_plugins(path, format)
             format = os.path.splitext(npath)[-1].lower().replace('.', '').upper()
             stream = lopen(npath, 'rb')
@@ -2169,7 +2167,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
             mi.timestamp = utcnow()
         if mi.pubdate is None:
             mi.pubdate = utcnow()
-        self.set_metadata(id, mi, ignore_errors=True)
+        self.set_metadata(id, mi, ignore_errors=True, commit=True)
         if preserve_uuid and mi.uuid:
             self.set_uuid(id, mi.uuid, commit=False)
         for path in formats: