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<h1 class="topictitle1">Usage notes: Commitment control</h1>
<div><p>The commit and rollback operations are available in several <span class="keyword">iSeries™</span> programming languages, including
the RPG/400<sup>®</sup>, COBOL/400<sup>®</sup>,
PL/I, SQL, and the i5/OS™ control language (CL). You can open logical files
for output under commitment control when underlying physical files are journaled
to different journals. Commitment control can also be used in a batch environment.</p>
<p>However, the checks for violations are deferred if a record change affects
underlying physical files that are journaled to the same journal.
If the record change affects underlying physical files that are not journaled
to the same journal, and it causes a duplicate key or referential constraint
violation, an error will occur during the input/output operation. For example,
assume physical file A with a unique key is journaled to journal X, while
physical file B with a unique key is journaled to journal Y. Logical file
C is created over physical files A and B and opened under commitment control.
A delete operation performed using logical file C removes a record from physical
file A with key K. It is possible to add a record back to physical file A
with key K before the transaction is committed. However, an attempt to add
a record to physical file B with key K, before the transaction is committed,
will fail since physical files A and B are journaled to different journals.</p>
<p>Just as it provides assistance in interactive transaction recovery, commitment
control can also help in batch job recovery. </p>
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rbaforzahfprg.htm" title="Commitment control lets you define and process a number of changes to database files in a single unit (transaction). It can ensure that complex application transactions are logically synchronized, even if the job or system ends. Two-phase commitment control ensures that committable resources, such as database files on multiple systems, remain synchronized.">Ensure data integrity with commitment control</a></div>
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<div class="relconcepts"><strong>Related concepts</strong><br />
<div><a href="../sqlp/rbafydicomm.htm">Commitment control</a></div>
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