63 lines
5.6 KiB
HTML
63 lines
5.6 KiB
HTML
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<meta name="abstract" content="Some optional functions available with journal management can significantly increase auxiliary storage requirements." />
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<title>Functions that increase the journal receiver size</title>
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<h1 class="topictitle1">Functions that increase the journal receiver size</h1>
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<div><p>Some optional functions available with journal management can significantly increase auxiliary storage requirements.</p>
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<p>You can select to journal both before-images and after-images. The system uses more storage if you select both before-images and after-images, although storage use is not necessarily doubled. If you
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journal access paths, the before-images and after-images are written to the journal receiver when a database file is updated. Only after-images are written when a database file is added (write operation)
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or deleted. Neither the before-image nor after-image is deposited into the journal if the after-image is exactly the same as the before-image.</p>
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<p>Using Fixed-length options for journal entries can also increase auxiliary storage requirements. The additional storage that fixed-length options use is similar to the extra space that is used by journaling
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both before-images after-images.</p>
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<p>The system requires additional space to journal access paths. The space required depends on the following items:</p>
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<ul><li>How many access paths are journaled.</li>
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<li>How often you change the access paths. When you update a record in a database file, you cause an access path journal entry only if you update a field included in the access path.</li>
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<li>The method used to update access paths. More journal entries are written if you update access paths randomly than if you update them in ascending or descending sequence. Doing a mass change to an access
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path field, such as a date change, causes the fewest journal entries.</li>
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</ul>
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<p>If you are using system-managed access-path protection and you journal database files, the system uses the same journal receiver to protect access paths for that file. This also increases the size of
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your journal receivers.</p>
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<p>The information in Methods to estimate a journal receiver will help you predict your requirements for auxiliary storage.</p>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rzakiplnuseaux.htm" title="If you are journaling an object, journal management writes a copy of every object change to the journal receiver. It writes additional entries for object level activity, such as opening and closing the object, adding a member, or changing an object attribute. If you have a busy system and journal many objects, your journal receivers can quickly become very large.">Plan for journal use of auxiliary storage</a></div>
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</div>
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<div class="relconcepts"><strong>Related concepts</strong><br />
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<div><a href="rzakiintrusion.htm" title="You can use the Fixed Length Data (FIXLENDTA) parameter of Create Journal (CRTJRN) and Change Journal (CHGJRN) commands to audit security related activity for journaled objects on your system.">Fixed-length options for journal entries</a></div>
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<div><a href="rzakismappintro.htm" title="System-managed access-path protection (SMAPP) allows you to use some of the advantages of journaling without explicitly setting up journaling. Use SMAPP to decrease the time it takes to restart your system after an abnormal end.">System-managed access-path protection</a></div>
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</div>
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<div class="reltasks"><strong>Related tasks</strong><br />
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<div><a href="rzakiestimatercv.htm" title="You can use the methods below to estimate the effect a journal receiver will have on auxiliary storage.">Methods to estimate the size of a journal receiver</a></div>
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