Types of cursor locks and explanation each of them ?
Answer Posted / kalyan dhara
FOR UPDATE and CURRENT OF
---------------
When you issue a SELECT...FOR UPDATE statement, the RDBMS
automatically obtains exclusive row-level locks on all the
rows identified by the SELECT statement, holding the records
“for your changes only” as you move through the rows
retrieved by the cursor. No one else will be able to change
any of these records until you perform a ROLLBACK or a COMMIT.
CURSOR toys_cur IS
SELECT name, manufacturer, preference_level,
sell_at_yardsale_flag
FROM my_sons_collection
WHERE hours_used = 0
FOR UPDATE;
UPDATE table_name
SET set_clause
WHERE CURRENT OF toys_cur ;
OR
DELETE FROM table_name
WHERE CURRENT OF toys_cur ;
| Is This Answer Correct ? | 2 Yes | 0 No |
Post New Answer View All Answers
What are the types of keys?
what does it mean to have quoted_identifier on? : Sql dba
Why query optimization is needed?
Explain what is sql*plus?
What is sql and also describe types of sql statements?
Does sql between include endpoints?
How can we make an if statement within a select statement?
Advantages and disadvantages of stored procedure?
What are predefined functions in sql?
Why is partition used in sql?
What is trigger and how to use it in sql?
how to enter characters as hex numbers? : Sql dba
What is column?
what tools available for managing mysql server? : Sql dba
How do I upgrade sql?