Release 10.1A: OpenEdge Data Management:
DataServer for Microsoft SQL Server

Defining the ROWID

When you create or update a schema holder, the DataServer uses the following guidelines to select a column in a 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. To create a PROGRESS_RECID column, see the "Modifying tables to create PROGRESS_RECID in support of the ROWID function" section.
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:
Unique, single-component, mandatory, integer.
Unique, single-component, integer.
Unique, single-component, mandatory, any data type except float.
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.

The DataServer allocates a buffer to hold the key information for the selected index. The buffer is 245 bytes by default. If the index you select is a multi-component index, this may be inadequate. The size of the buffer can be modified with the -Dsrv ZPRGRS_RECID_BUF_SIZE,n option. See the "RECID Buffer size: The ZPRGRS_RECID_BUF_SIZE,nnn Option" section for more information on setting this option.

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.

To select an index to support the ROWID function, use the following procedure in the Data Dictionary with the schema holder connected (you do not have to connect to the MS SQL Server database).

To select an index to support the ROWID function:

Choose Tables mode.
Select the table whose ROWID you want to modify.
Choose Table Properties.
Choose DataServer. The following dialog box appears:



Double-click an index to see detailed information on its attributes. The following dialog box appears:



Choose OK to return to the ROWID Choices dialog box.
Select the index you want to use to support ROWID.
Choose OK to return to the Table Properties dialog box.