After you declare a cursor, you must open it to fetch, update, or delete rows. Opening a cursor lets Adaptive Server begin to create the cursor result set by evaluating the select statement that defines the cursor and makes it available for processing.
open cursor_name
You cannot open a cursor that is already open or that has not been defined with the declare cursor statement. You can reopen a closed cursor to reset the cursor position to the beginning of the cursor result set.
Depending on the cursor’s type and the query plan, a worktable may be created and populated when you open the cursor.