The concept of locks is closely related to the concept of transaction isolation. Transaction isolation makes sure that two simultaneously running transactions do not affect each other. Transaction isolation levels are realized by setting locks on read or changed rows in a database table. Databases provide multiple isolation levels that determine how strong the isolation is between two simultaneously running transactions. Experience shows that if the isolation is stronger, throughput and scalability decrease.

We recommend that you choose a locking strategy and apply it consistently throughout all application components. You can choose from two available locking techniques: