Using the SCROLL Keyword to Create a Scroll Cursor

Use the SCROLL keyword to create a scroll cursor, which can fetch rows of the active set in any sequence.

The database server retains the active set of the cursor as a temporary table until the cursor is closed. You can fetch the first, last, or any intermediate rows of the active set as well as fetch rows repeatedly without having to close and reopen the cursor. (See FETCH.)

On a multiuser system, the rows in the tables from which the active-set rows were derived might change after the cursor is opened and a copy is made in the temporary table. If you use a scroll cursor within a transaction, you can prevent copied rows from changing either by setting the isolation level to Repeatable Read or by locking the entire table in share mode during the transaction. (See SET ISOLATION and LOCK TABLE.)

The following example creates a scroll cursor for a SELECT statement: 
DECLARE sc_cur SCROLL CURSOR FOR SELECT * FROM orders;

You can create scroll cursors as Select and Function cursors but not as Insert cursors. Scroll cursors cannot be declared as FOR UPDATE.