code: public Integer getNewTableIndex(final String _tableName,
                                      final String _column,
                                      final Integer _relIndex,
                                      final Long _clazzId)
      {
          this.tableIndex++;
          this.sqlTable2Index.put(_relIndex + "__" + _tableName + "__" + _column
                          + (_clazzId == null ? "" : "__" + _clazzId), this.tableIndex);
          return this.tableIndex;
      }
docs: Get a new table index and add the table to the map of existing table
  indexes.
  
  @param _tableName tablename the index is wanted for
  @param _column name of the column, used for the relation
  @param _relIndex relation the table is used in
  @param _clazzId optional id of the classification
  @return new index for the table