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.
See “Effect of rollback” for what happens to cursors during a rollback of the database.
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.
