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Background documentation Isolation Level Locate the document in its SAP Library structure

The isolation level has an important role to play in the lock activities of the database system. You use the isolation level to specify whether locks are requested or released implicitly, and how.

Your choice of isolation level has consequences for the degree of parallelism of competing transactions and the consistency of the data: the lower the value of the isolation level, the higher the degree of parallelism, and the lower the degree of guaranteed consistency. If transactions are competing for access to the same data, then different isolation levels can cause different inconsistent phenomena. You must find a compromise between parallelism and consistency, while also taking into account the requirements of your database application.

You can specify the isolation level with the CONNECT statement when, for example, you open a database session.

The following isolation levels exist:

·        Isolation level 0 (uncommitted)

·        Isolation level 1 or 10 (committed)

·        Isolation level 15

·        Isolation level 2 or 20 (repeatable)

·        Isolation level 3 or 30 (serializable)

 

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