code: @Override
      public TableIdx getJoinTableIdx(final SQLSelect _sqlSelect)
          throws CacheReloadException
      {
          final String tableName = ((SQLTable) getTable()).getSqlTable();
          return _sqlSelect.getIndexer().getTableIdx(tableName, this.attribute.getName(),
                          this.startType.getMainTable().getSqlTable());
      }
docs: Gets the join table idx.
  
  @param _sqlSelect the sql select
  @return the join table idx
  @throws CacheReloadException the cache reload exception