docs: public Object generateKey(FieldList record)
      {
          if (record.isQueryRecord())
              return record;      // These can't be shared
          else if ((record.getDatabaseType() & Constants.TABLE_TYPE_MASK) == Constants.UNSHAREABLE_MEMORY)   // Special sharable temp memory file
              return record;      // These can't be shared
          else
              return this.getUniqueFilePath(record);  // These can be shared
      }