@Signature
  public String getPredicateString() {
    if (filterExpr == null) {
      return null;
    }
    return PlanUtils.getExprListString(Arrays.asList(filterExpr));
  }
A boolean variable set to true by the semantic analyzer only in case of the analyze command.
ql/src/java/org/apache/hadoop/hive/ql/plan/TableScanDesc.java