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<h1>Persistent and transient fields</h1><div id="TOC"><div id="TOCinner"><span class="TOCtitle">Contents</span><div class="TOCcontents"><ul><li><a href ="#Advantage">Advantage</a></li><li><a href ="#Effect">Effect</a></li><li><a href ="#Alternate strategies">Alternate strategies</a></li></ul></li></ul></div></div></div>
<p>Do not create fields that you don't need for persistence</p>
<a name="Advantage"></a><h2>Advantage</h2>
<p>Storing only needed information will help to keep your database footprint as small as possible.</p>
<a name="Effect"></a><h2>Effect</h2>
<p>If your persistent class contains fields that do not need to be stored you should mark them as transient to prevent them from being stored:</p>
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<p>.NET:<br><code>public class NotStorable {<br> [Transient] private int length;<br>. . . <br>}</code></p>
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<p>You can use <a href="../../implementation_strategies/callbacks.html" class="wikiLink">Callbacks</a> or <a href="../../implementation_strategies/translators.html" class="wikiLink">Translators</a> to set transient fields on retrieval.</p>
<p>Also avoid storing classes having only transient information - their indexes' maintenance will produce unnecessary performance overhead.</p>
<a name="Alternate strategies"></a><h2>Alternate strategies</h2>
<p>In some cases you may want to persist class meta-information without the actual object data. The example can be database singleton for <a href="../../client-server/remote_code_execution.html" class="wikiLink">remote code execution</a></p></div>
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This revision (9) was last Modified 2007-05-07T16:29:51 by Tetyana.
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