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<h1 class="topictitle1">Access intent of a committable resource</h1>
<div><p>The access intent determines how the resources participate together
in a transaction.</p>
<p>When a resource is placed under commitment control, the resource manager
indicates how the resource will be accessed:</p>
<ul><li>Update</li>
<li>Read-only</li>
<li>Undetermined</li>
</ul>
<p> The following table shows what access intents are possible for a particular
type of resource and how the system determines the access intent for a resource
when it is registered.</p>
<div class="tablenoborder"><table cellpadding="4" cellspacing="0" summary="" frame="border" border="1" rules="all"><thead align="left"><tr><th valign="top" id="d0e30">Resource type</th>
<th valign="top" id="d0e32">Possible access intents</th>
<th valign="top" id="d0e34">How the access intent is determined</th>
</tr>
</thead>
<tbody><tr><td valign="top" headers="d0e30 ">FILE</td>
<td valign="top" headers="d0e32 ">Update, read-only</td>
<td valign="top" headers="d0e34 ">Based on how the file was opened</td>
</tr>
<tr><td valign="top" headers="d0e30 ">DDL</td>
<td valign="top" headers="d0e32 ">Update</td>
<td valign="top" headers="d0e34 ">Always update</td>
</tr>
<tr><td valign="top" headers="d0e30 ">API</td>
<td valign="top" headers="d0e32 ">Update</td>
<td valign="top" headers="d0e34 ">Always update</td>
</tr>
<tr><td valign="top" headers="d0e30 ">DDM</td>
<td valign="top" headers="d0e32 ">Update, read-only</td>
<td valign="top" headers="d0e34 ">Based on how the file was opened</td>
</tr>
<tr><td valign="top" headers="d0e30 ">LU62</td>
<td valign="top" headers="d0e32 ">Undetermined</td>
<td valign="top" headers="d0e34 ">Always undetermined</td>
</tr>
<tr><td valign="top" headers="d0e30 ">DRDA<sup>®</sup></td>
<td valign="top" headers="d0e32 ">Update, read-only, undetermined</td>
<td valign="top" headers="d0e34 ">For DRDA Level
1, the access intent is update if no other remote resources are registered.
Otherwise, the access intent is read-only. For DRDA Level 2, the access intent is always
undetermined.</td>
</tr>
<tr><td valign="top" headers="d0e30 ">TCP</td>
<td valign="top" headers="d0e32 ">Undetermined</td>
<td valign="top" headers="d0e34 ">Always undetermined</td>
</tr>
</tbody>
</table>
</div>
<p>The access intent of resources that are already registered determines whether
a new resource can be registered. The following rules apply:</p>
<ul><li>A one-phase resource whose access intent is update cannot be registered
when any of the following conditions is true: <ul><li>Resources whose access intent is update are already registered at other
locations.</li>
<li>Resources whose access intent is undetermined are already registered at
other locations.</li>
<li>Resources whose access intent is undetermined are already registered at
the same location and the resources have been changed during the current transaction.</li>
</ul>
</li>
<li>A two-phase resource whose access intent is update cannot be registered
when a one-phase resource whose access intent is update is already registered.</li>
</ul>
</div>
<div>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="rzakjresources.htm" title="When you place an object under commitment control, it becomes a committable resource. It is registered with the commitment definition. It participates in each commit operation and rollback operation that occurs for that commitment definition.">How commitment control works with objects</a></div>
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