why major_compaction does more performance consumption than minor_compaction ?

[Fx_Bull]

hello everyone!


Differenct between them:


1、minor_compact will select best storeFiles to compact。
2、major_compact will select all storeFiles to compact and do some clean work。


RegionServer holds only one compactSplitThread ，and only one compact task run !


3、The compaction task just scans all the storefiles and then merge one, so I 
hold the opinon that major compact only cost more time than minor .


best regards!!