Click here to view and discuss this page in DocCommentXchange. In the future, you will be sent there automatically.

SQL Anywhere 12.0.0 (Français) » SQL Anywhere Server - SQL Usage » Using transactions and isolation levels » How locking works » Row locks

 

Write locks

A transaction acquires a write lock whenever it inserts, updates, or deletes a row. This is true for transactions at all isolation levels, including isolation level 0 and snapshot isolation levels. No other transaction can obtain a read, intent, or write lock on the same row after a write lock is acquired. Write locks are also referred to as exclusive locks because only one transaction can hold an exclusive lock on a row at any time. No transaction can obtain a write lock while any other transaction holds a lock of any type on the same row. Similarly, once a transaction acquires a write lock, requests to lock the row by other transactions are denied.