Store Postgres HLL buckets during Usage Ping calculation
Backgroun
From &5227 (closed)
Right now
PostgresHllBatchDistinctCounter
buckets which are built for purpose of estimating every particular count calculated with this counter are not stored anywhere. In order to be able to fully utilize HLL advantages, that allows to merge hll buckets of multiple metrics in order to get number of unique elements in union of this sets, we need to persist hll buckets calculated for single metrics, in order to reuse them later on when aggregated metrics will be calculated.