SQL backend to handle big data

the collector and notification worker only works on a single thread... enabling collector to use multiple workers causes massive amount of deadlocks because of updating done to source/project/user/resource tables. these tables do nothing to help queries and only act as a bottleneck or point of deadlock when recording metering data. we should store raw Samples and not update anything... queries can be done against Sample with the same/better performance as current design.