disable-optimize-without-commit.patch

diff --git a/haystack/backends/solr_backend.py b/haystack/backends/solr_backend.py
index 777e35f..d1a05b0 100644
--- a/haystack/backends/solr_backend.py
+++ b/haystack/backends/solr_backend.py
@@ -103,8 +103,9 @@ class SolrSearchBackend(BaseSearchBackend):
 
                 self.conn.delete(q=" OR ".join(models_to_delete), commit=commit)
 
-            # Run an optimize post-clear. http://wiki.apache.org/solr/FAQ#head-9aafb5d8dff5308e8ea4fcf4b71f19f029c4bb99
-            self.conn.optimize()
+            if commit:
+                # Run an optimize post-clear. http://wiki.apache.org/solr/FAQ#head-9aafb5d8dff5308e8ea4fcf4b71f19f029c4bb99
+                self.conn.optimize()
         except (IOError, SolrError) as e:
             if not self.silently_fail:
                 raise