public static void replaceTabAlias(Collection<ExprNodeDesc> exprs, String oldAlias, String newAlias) {
    if (exprs != null) {
      for (ExprNodeDesc expr : exprs) {
        replaceTabAlias(expr, oldAlias, newAlias);
      }
    }

  }
Checks wether the two expression sets have a common deterministic intersection.
ql/src/java/org/apache/hadoop/hive/ql/plan/ExprNodeDescUtils.java