@Explain(displayName = "residual filter predicates", explainLevels = { Level.USER, Level.DEFAULT, Level.EXTENDED })
  public String getResidualFilterExprsString() {
    if (getResidualFilterExprs() == null || getResidualFilterExprs().size() == 0) {
      return null;
    }

    StringBuilder sb = new StringBuilder();
    boolean first = true;
    for (ExprNodeDesc expr : getResidualFilterExprs()) {
      if (!first) {
        sb.append(" ");
      }

      first = false;
      sb.append("{");
      sb.append(expr.getExprString());
      sb.append("}");
    }

    return sb.toString();
  }
Get the string representation of filters.

Returns null if they are no filters.

@return Map from alias to filters on the alias.
ql/src/java/org/apache/hadoop/hive/ql/plan/JoinDesc.java