public String getTimeColumnName() {
      return timeColumnName;
    }
<b>Optimization phase:</b> Distributed plan planning.

<p>This optimize rule implement the rules below.
<li>When order by time and there is only one device entry in DeviceTableScanNode below, the
    SortNode can be eliminated.
<li>When order by all IDColumns and time, the SortNode can be eliminated.
<li>When StreamSortIndex==OrderBy size()-1, remove this StreamSortNode
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/optimizations/SortElimination.java