optimize GenderStats model

contrib/src/web/database.py

@@ -36,15 +36,13 @@ class BaseModel(Model):
 
 class GenderStats(BaseModel):
     rowid = IntegerField()
-    t = CharField(column_name='t_id', max_length=10)
-    t_ts = DateTimeField(default=currentTime)
+    t = CharField(column_name='t_id', max_length=10, index=True)
+    t_ts = DateTimeField(default=currentTime, index=True)
     gender_text = CharField(null=True, max_length=100)
 
     class Meta:
         table_name = 'gender_stats'
-        indexes = (
-            (('t', 't_ts', 'rowid'), True),
-        )
+        # primary_key is implicitly indexed
         primary_key = CompositeKey('rowid', 't', 't_ts')
 
 def connect():