MDAC 2.5 SDK - ODBC Programmer's Reference
Appendix F: ODBC Cursor Library
An application calls SQLSetConnectAttr with the SQL_ATTR_ODBC_CURSORS attribute to specify whether the cursor library is always used, used if the driver does not support scrollable cursors, or never used. The cursor library assumes that a driver supports scrollable cursors if it returns SQL_CA1_RELATIVE for the SQL_STATIC_CURSOR_ATTRIBUTES1 information type in SQLGetInfo.
The application must call SQLSetConnectAttr to specify the cursor library usage after it calls SQLAllocHandle with a HandleType of SQL_HANDLE_DBC to allocate the connection and before it connects to the data source. If an application calls SQLSetConnectAttr with the SQL_ATTR_ODBC_CURSORS attribute while the connection is still active, the cursor library returns an error.
To set a statement attribute supported by the cursor library for all statements associated with a connection, an application must call SQLSetConnectAttr for that statement attribute after it connects to the data source and before it opens the cursor. If an application calls SQLSetConnectAttr with a statement attribute and a cursor is open on a statement associated with the connection, the statement attribute will not be applied to that statement until the cursor is closed and reopened.