Client Cursors
Both ODBC and DB-Library support client cursors, cursors implemented on the client. In a client cursor, a default result set is used to cache the entire result set on the client and all cursor operations are performed against this client cache. None of the server cursor functionality of Microsoft® SQL Server™ 2000 is used. Client cursors support only forward-only and static cursors, not keyset-driven or dynamic cursors.
The DB-Library client cursors were originally implemented before SQL Server supported server cursors. ODBC implements client cursors that use the ODBC Cursor Library. This is intended for use with ODBC drivers that support only the default settings for cursor characteristics. Because both DB-Library and the SQL Server ODBC driver offer full support for cursor operations through server cursors, limit the use of client cursors.
Client cursors should be used only to alleviate the restriction that server cursors do not support all Transact-SQL statements or batches. If a static scrolling cursor is needed on a Transact-SQL statement or batch that cannot be executed with a server cursor, consider using a client cursor.