protected void reserveMemory(long size) {
    usedMemory += size;
    memoryReservationManager.reserveMemoryCumulatively(size);
    if (usedMemory > maxUsedMemory) {
      maxUsedMemory = usedMemory;
      operatorContext.recordSpecifiedInfo(MAX_RESERVED_MEMORY, Long.toString(maxUsedMemory));
    }
  }
@return true if current right block is consumed up
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/operator/source/relational/AbstractMergeSortJoinOperator.java