static boolean isDeleteEventInRange(
          OrcRawRecordMerger.KeyInterval keyInterval,
          DeleteRecordKey deleteRecordKey) {
        if(keyInterval.getMinKey() != null &&
            deleteRecordKey.compareTo(keyInterval.getMinKey()) < 0) {
          //current deleteEvent is < than minKey
          return false;
        }
        if(keyInterval.getMaxKey() != null &&
            deleteRecordKey.compareTo(keyInterval.getMaxKey()) > 0) {
          //current deleteEvent is > than maxKey
          return false;
        }
        return true;
      }
number of events actually loaded in memory
ql/src/java/org/apache/hadoop/hive/ql/io/orc/VectorizedOrcAcidRowBatchReader.java