When you create or update a schema holder, the DataServer uses the following guidelines to select a column in an ODBC data-source table to support the ROWID function:
If the data-source table has a PROGRESS_RECID column, the DataServer selects that column. A column of this type provides optimal support for the ROWID function; you cannot select an alternative to it.
If the data-source table does not have a PROGRESS_RECID column, the DataServer evaluates the available indexes and selects one according to the following preferences:
1. Unique, single-component, mandatory, integer
2. Unique, single-component, integer
3. Unique, single-component, mandatory, any data type except float
4. Unique, multi-component, any data type
If more than one index in the data-source table meets the second level—unique, single-component, integer—the DataServer selects the first such index that it encounters to support the ROWID function. Note that the indexes in this class are not mandatory, hence it is essential that you enforce the column supporting ROWID as mandatory at least through code if not through definitions. If your application handles an index in such a way as to make it a better support for the ROWID function, you can designate it in the Data Dictionary.
Note: An index that you select as a ROWID must be defined as a unique index. It must also be mandatory, if not by definition, then by means of the application code.
You can select an index to support the ROWID function, in the Data Dictionary with the schema holder connected. (You do not have to connect to the ODBC data source.)
To select an index to support the ROWID function:
1. Click the Tables mode button.
2. Select the table whose ROWID you want to modify.
3. Click the Table Properties button.
4. Click the DataServer button. The ROWID Choices dialog box appears:
5. Double-click an index to see detailed information on its attributes. The following dialog box appears:
6. Click OK to return to the ROWID Choices dialog box.
7. Select the index that you want to use to support ROWID.
8. Click OK to return to the Table Properties dialog box.
If the data-source table has a PROGRESS_RECID column, the DataServer selects that column. A column of this type provides optimal support for the ROWID function; you cannot select an alternative to it.
