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<h1>Update Depth</h1><p>db4o update behavior is regulated by
<a href="../object_lifecycle/update_depth.html" class="wikiLink">Update Depth</a>. Understanding Update Depth
will help you to improve performance and avoid unnecessary memory
usage.
</p>
<p>When Update Depth is set to a big value
on objects with a deep reference hierarchy it will cause each update
on the top-level object to trigger updates on the lower-level
objects, which can impose a huge performance penalty.
</p>
<p>The following settings should be used
with a special care and only with a good reason to do so:</p>
<ol>
<li>
<p>Global deep update depth setting:</p>
<span name="cs_wiki_filter" csw_filters="net">
<p>.NET:</p>
<p><code>configuration.UpdateDepth(Int32.MAX_VALUE);</code></p>
</span>
<p>This setting causes ALL objects in the
database to be updated to the lowest possible level on each update.</p>
</li>
<li>
<p>Cascade on update:</p>
<span name="cs_wiki_filter" csw_filters="net">
<p>.NET:</p>
<p><code>configuration.ObjectClass(typeof(Item)).CascadeOnUpdateDepth(true);</code></p>
</span>
</li>
</ol>
<p>This setting will cause an update to
the lowest level for Item class only. This can be unnecessary and
therefore undesired in order to safe system resources.</p>
<p>For more detailed information, please,
refer to <a href="../object_lifecycle/update_depth.html" class="wikiLink">Update Depth</a>.</p></div>
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This revision (2) was last Modified 2007-09-02T18:02:41 by Tetyana.
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