Controlling ODBC Cursor Library Usage with the Single-Tier "Lite" Edition OLE DB Provider for ODBC Data Sources

The Single-Tier "Lite" Edition OLE DB Provider for ODBC Data Sources requires that the target ODBC driver support some form of scrollable cursor for any connection. To fully support OLE DB rowsets, the minimum requirements are --

• bookmark support
  
• absolute cursor positioning
  
• backward scrolling

KEYSET DRIVEN and STATIC cursors both support this functionality.

If the Single-Tier "Lite" Edition OLE DB Provider for ODBC Data Sources is to be used with an ODBC driver which natively supports neither KEYSET DRIVEN nor STATIC cursors, then the Microsoft ODBC Cursor Library must be used. The Microsoft ODBC Cursor Library only supports STATIC cursors, but this is generally sufficient.

All OpenLink ODBC drivers support both KEYSET DRIVEN and STATIC cursors, and it is best to use the driver's cursors.

The Single-Tier "Lite" Edition OLE DB Provider for ODBC Data Sources uses the provider-specific keyword Cursors in the Extended Properties part of the OLE DB connect string, to control cursor library usage. This keyword can be set to one of three values:

• ODBC
  
• Driver
  
• IfNeeded

Each setting is analogous to the ODBC counterpart SQL_CUR_USE_xxx. The default behavior is Cursors=IfNeeded.

The table below lists the recommended Cursor settings for various ODBC drivers when used with the Single-Tier "Lite" Edition OLE DB Provider for ODBC Data Sources --

ODBC Driver	Cursor setting	Comments
All OpenLink ODBC drivers	Driver or IfNeeded (default)	The scrollable cursor support built into our drivers provides the necessary functionality.
Native Microsoft SQL Server driver	ODBC	The driver's native scrollable cursor support is inadequate.