@Override
  public void setDpPartSpecs(Collection<Partition> dpPartSpecs) {
    this.dpPartSpecs = dpPartSpecs;
  }
Get the list of partitions that need to update statistics.
TODO: we should reuse the Partitions generated at compile time
since getting the list of partitions is quite expensive.

@return a list of partitions that need to update statistics.
@throws HiveException
ql/src/java/org/apache/hadoop/hive/ql/stats/BasicStatsTask.java