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Background documentation Transaction Locate the document in its SAP Library structure

A transaction is a series of SQL statements that are handled as a unit by the database system; in a transaction, either all the database changes resulting from the SQL statements are represented in the database state, or none of the changes exist in the database.

The transaction manager of the database system ensures, among other things, that parallel transactions from multiple database sessions are processed correctly, and deliver the same results as they would if processed sequentially.

The first transaction is opened when an SQL session is opened. A transaction is completed using a COMMIT or ROLLBACK, with the following effects:

·        If the transaction has been completed successfully with a COMMIT, all database changes are permanent.

·        If a transaction is ended with a ROLLBACK, or terminated in any other way, all the database changes made during the transaction are reversed.

Both a COMMIT and a ROLLBACK open a new transaction implicitly.

Since the database system allows access by competing transactions to the same database objects, locks are required to isolate individual transactions.

See also:

·        Reference Manual, Transactions

·        Concepts of the Database System, Locks

 

 

 

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