When you use cursors, Sybase IQ needs to 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 then update that table later on at time y. Sybase IQ needs to retain the version of the customer table from time x until you are done using cust_cursor.
The support of cursors by Sybase IQ is oriented toward their likely use in DSS applications. The following sections discuss specific cursor characteristics with implications for transaction processing.