## Description <!--- Provide a general summary of the issue in the Title above --> blobdb功能开启后,KVTtlCompactionFilter::FilterBlobByKey()需要读取value,进行string类型的过期判断,导致读压力较大,考虑优化相关性能。 ## Expected Behavior <!--- tell us how it should work --> ## Current Behavior <!--- explain the difference from expected behavior --> ## Possible Solution <!--- Not obligatory, but suggest a fix/reason for the feature --> <!--- or ideas how to implement the addition or change --> ## Context <!--- How has this issue affected you? What are you trying to accomplish? -->