[cloudkitty] No indexes in the rated_data_frames table

Hi, Very fast, with only a few resources, the rated_data_frames tables becomes huge. I was very surprised to see there's absolutely zero index in this table. Isn't a "openstack rating dataframes get" querying this table, with tenant_id and begin / end as filters? Wouldn't the API calls be a lot more efficient with such indexes? Cheers, Thomas Goirand (zigo)