Today key points
1. Updated the codereview. Changed to storing also the subscribed_items meta as content itemid.
2. Got familiar with whoosh, wrote some sample code to check for some usecases. Assembled the yesterday talk and wrote on EP a way to handle subscribers list using the whoosh indexer and determining the subscribers list at the moment when item is modified (same as it was before, but faster).
Plans for tomorrow
Update user methods.
Implement the section 1.4 from EP if it gets to be approved.