Committing a transaction

    Available

    DSQL, ESQL

    Syntax

    The COMMIT statement commits all work carried out in the context of this transaction (inserts, updates, deletes, selects, execution of procedures). New record versions become available to other transactions and, unless the RETAIN clause is employed, all server resources allocated to its work are released.

    If any conflicts or other errors occur in the database during the process of committing the transaction, the transaction is not committed and the reasons are passed back to the user application for handling and the opportunity to attempt another commit or to roll the transaction back.

    COMMIT Options

    • The optional keyword WORK is supported just for compatibility with other relational database management systems that require it.

    • The clause is used for the “soft” commit, variously referred to amongst host languages and their practitioners as COMMIT WITH RETAIN, CommitRetaining, “warm commit”, et al. The transaction is committed but some server resources are retained and the transaction is restarted transparently with the same Transaction ID. The state of row caches and cursors is kept as it was before the soft commit.

      For soft-committed transactions whose isolation level is SNAPSHOT or SNAPSHOT TABLE STABILITY, the view of database state is not updated to reflect changes by other transactions, and the user of the application instance continues to have the same view as when the transaction started originally. Changes made during the life of the retained transaction are visible to that transaction, of course.

    Recommendation

    Use of the COMMIT statement in preference to ROLLBACK is recommended for ending transactions that only read data from the database, because COMMIT consumes fewer server resources and helps to optimize the performance of subsequent transactions.

    See also

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