private void fixContextReferences(SelectOperator cSEL, SelectOperator pSEL) {
      Collection<Map<String, Operator<? extends OperatorDesc>>> mapsAliasToOpInfo =
              new ArrayList<Map<String, Operator<? extends OperatorDesc>>>();
      for (JoinOperator joinOp : pctx.getJoinOps()) {
        if (joinOp.getConf().getAliasToOpInfo() != null) {
          mapsAliasToOpInfo.add(joinOp.getConf().getAliasToOpInfo());
        }
      }
      for (MapJoinOperator mapJoinOp : pctx.getMapJoinOps()) {
        if (mapJoinOp.getConf().getAliasToOpInfo() != null) {
          mapsAliasToOpInfo.add(mapJoinOp.getConf().getAliasToOpInfo());
        }
      }
      for (Map<String, Operator<? extends OperatorDesc>> aliasToOpInfo : mapsAliasToOpInfo) {
        for (Map.Entry<String, Operator<? extends OperatorDesc>> entry : aliasToOpInfo.entrySet()) {
          if (entry.getValue() == cSEL) {
            aliasToOpInfo.put(entry.getKey(), pSEL);
          }
        }
      }
    }
Change existing references in the context to point from child to parent operator.
@param cSEL child operator (to be removed, and merged into parent)
@param pSEL parent operator
ql/src/java/org/apache/hadoop/hive/ql/optimizer/NonBlockingOpDeDupProc.java