This adds an index on the 'param' column in the b2b_entities table for mysql. When opensips deletes from the b2b_entities table it only references the param column. Without an index this forces mysql to do a full table scan for every delete. This index should greatly speed up these queries.
Adding this index on our production system cut mysql cpu usage by more than half.
I also bumped the table version for b2b_entities and updated the db schema (hope I did this correctly).