private String getClause() {
   if (clauseName == null) {
     TreeSet<String> ks = new TreeSet<String>(qb.getParseInfo().getClauseNames());
     clauseName = ks.first();
   }
   return clauseName;
 }
  public void print() {
    if (!log.isDebugEnabled()) {
      return;
    }
    StringBuilder builder = new StringBuilder();
    builder.append("ASTNode:" + ast.dump() + "\n");
    builder.append("QB:");
    builder.append("\n numJoins:" + qb.getNumJoins());
    builder.append("\n numGbys:" + qb.getNumGbys());
    builder.append("\n numSels:" + qb.getNumSels());
    builder.append("\n numSelDis:" + qb.getNumSelDi());
    builder.append("\n aliasToTabs:");
    Set<String> tabAliases = qb.getTabAliases();
    for (String alias : tabAliases) {
      builder.append("\n\t" + alias + ":" + qb.getTabNameForAlias(alias));
    }
    builder.append("\n aliases:");
    for (String alias : qb.getAliases()) {
      builder.append(alias);
      builder.append(", ");
    }
    builder.append("id:" + qb.getId());
    builder.append("isQuery:" + qb.getIsQuery());
    builder.append("\n QBParseInfo");
    QBParseInfo parseInfo = qb.getParseInfo();
    builder.append("\n isSubQ: " + parseInfo.getIsSubQ());
    builder.append("\n alias: " + parseInfo.getAlias());
    if (parseInfo.getJoinExpr() != null) {
      builder.append("\n joinExpr: " + parseInfo.getJoinExpr().dump());
    }
    builder.append("\n hints: " + parseInfo.getHints());
    builder.append("\n aliasToSrc: ");
    for (String alias : tabAliases) {
      builder.append("\n\t" + alias + ": " + parseInfo.getSrcForAlias(alias).dump());
    }
    TreeSet<String> clauses = new TreeSet<String>(parseInfo.getClauseNames());
    for (String clause : clauses) {
      builder.append("\n\t" + clause + ": " + parseInfo.getClauseNamesForDest());
    }
    String clause = clauses.first();
    if (parseInfo.getWhrForClause(clause) != null) {
      builder.append("\n whereexpr: " + parseInfo.getWhrForClause(clause).dump());
    }
    if (parseInfo.getGroupByForClause(clause) != null) {
      builder.append("\n groupby expr: " + parseInfo.getGroupByForClause(clause).dump());
    }
    if (parseInfo.getSelForClause(clause) != null) {
      builder.append("\n sel expr: " + parseInfo.getSelForClause(clause).dump());
    }
    if (parseInfo.getHavingForClause(clause) != null) {
      builder.append("\n having expr: " + parseInfo.getHavingForClause(clause).dump());
    }
    if (parseInfo.getDestLimit(clause) != null) {
      builder.append("\n limit: " + parseInfo.getDestLimit(clause));
    }
    if (parseInfo.getAllExprToColumnAlias() != null
        && !parseInfo.getAllExprToColumnAlias().isEmpty()) {
      builder.append("\n exprToColumnAlias:");
      for (Map.Entry<ASTNode, String> entry : parseInfo.getAllExprToColumnAlias().entrySet()) {
        builder.append("\n\t expr: " + entry.getKey().dump() + " ColumnAlias: " + entry.getValue());
      }
    }
    if (parseInfo.getAggregationExprsForClause(clause) != null) {
      builder.append("\n aggregateexprs:");
      for (Map.Entry<String, ASTNode> entry :
          parseInfo.getAggregationExprsForClause(clause).entrySet()) {
        builder.append("\n\t key: " + entry.getKey() + " expr: " + entry.getValue().dump());
      }
    }
    if (parseInfo.getDistinctFuncExprsForClause(clause) != null) {
      builder.append("\n distinctFuncExprs:");
      for (ASTNode entry : parseInfo.getDistinctFuncExprsForClause(clause)) {
        builder.append("\n\t expr: " + entry.dump());
      }
    }

    if (qb.getQbJoinTree() != null) {
      builder.append("\n\n JoinTree");
      QBJoinTree joinTree = qb.getQbJoinTree();
      printJoinTree(joinTree, builder);
    }

    if (qb.getParseInfo().getDestForClause(clause) != null) {
      builder.append("\n Destination:");
      builder.append("\n\t dest expr:" + qb.getParseInfo().getDestForClause(clause).dump());
    }
    log.debug(builder.toString());
  }