When you use cursors, SAP Sybase IQ must be able to manage multiple versions within a single transaction.
For example, assume that you open a cursor called cust_cursor at time x that uses the customer table. You update that table at time y. SAP Sybase IQ retains the version of the customer table from time x until you are done using cust_cursor.
The support of cursors by SAP Sybase IQ is oriented toward their likely use in DSS applications.