count not use.

columnStore currently only doing level 0 and level 1 compaction,but the full functionality is available.

FloatPreAgg If you change the order of the elements in the structure, remember to modify marshal() and unmarshal() as well.

IntegerPreAgg If you change the order of the elements in the structure, remember to modify marshal() and unmarshal() as well.

IteratorByBlock for single mst.

MetaIndex If you change the order of the elements in the structure, remember to modify marshal() and unmarshal() as well.

Segment offset/size/minT/maxT.

StringPreAgg If you change the order of the elements in the structure, remember to modify marshal() and unmarshal() as well.