Live query block UI in iOS App

I am working on an iOS application, I have implemented 3 different live queries in it, when live query notifies for a change the app UI freezes till the execution ends. On observing I have noticed that live query executes in main thread even though I had executed it in background thread and I called my db instance in background. Please help me out that how could I force couch base to execute query on background thread.

BTW I am using couchbase version 2.1.1.

V2.1.1 is pretty old. As of V2.6, Live queries do not run on the UI thread.

Thank you for the response,I will update version and response back

Thank you, It worked fine after framework upgradation.