Cursors allow multiple threads, conditional processing, and debugging by providing the ability to iterate through result sets from a SELECT statement. Cursors return a result set as a cursor object that points to records that can then be updated or processed individually by moving to the next or previous record in the set. For updating, a cursor can be declared from a SELECT statement and used in subsequent DML statements with a FOR UPDATE clause to lock and update records in the result set one by one.

1. Another useful item in transaction is cursors. Cursors can be used to have multiple threads going,
conditional processing, and debugging (to name a few). How can you implement them with
transactions?
Solution
1)SELECT
2)UPDATE
SELECT Cursor :-
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"select emp_id,emp_name from EMPLOYEES where salary > 10000".
After execution of the above statement result is given as Cursor object
Result set is Data in table if Data belongs to one table otherwise a Virual table if data is from
more
that one Table(Select statement with Joining tables)
By default Cursor points to first record of result set
We have to Move next (fetch next record), Prev (fetch previous recors)
UPDATE Cursor :-
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CURSOR toys_cur IS
SELECT name, manufacturer, preference_level, sell_at_yardsale_flag
FROM my_sons_collection
WHERE hours_used = 0
FOR UPDATE;