# C1.LiveLinq.IndexingHintAction

## Content

<div class="doc-site-dotnet-api-container">




  <h1 id="C1_LiveLinq_IndexingHintAction" data-uid="C1.LiveLinq.IndexingHintAction" class="text-break">IndexingHintAction Enum
</h1>
  <div class="markdown level0 summary"><p>Specifies the actions taken by LiveLinq query optimizer when it encounters an
<b>Indexed()</b> hint applied to an expression (usually, a property) in a query.</p>
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  <div class="markdown level0 conceptual"></div>
  <h6><strong>Namespace</strong>: <a class="xref" href="C1.LiveLinq.html">C1.LiveLinq</a></h6>
  <h6><strong>Assembly</strong>: C1.LiveLinq.4.8.dll</h6>
  <h5 id="C1_LiveLinq_IndexingHintAction_syntax">Syntax</h5>
  <div class="codewrapper">
    <pre><code class="lang-csharp hljs">public enum IndexingHintAction</code></pre>
  </div>
  <div class="codewrapper">
    <pre><code class="lang-vbnet hljs">Public Enum IndexingHintAction</code></pre>
  </div>
  <h3 id="fields">Fields
</h3>
  <table class="table table-bordered table-condensed">
    <thead>
      <tr>
        <th>Name</th>
        <th>Description</th>
      </tr>
    <thead>
    </thead></thead><tbody>
      <tr>
        <td id="C1_LiveLinq_IndexingHintAction_Mandatory">Mandatory</td>
        <td><p>Create an index for this expression, if such index does not already exist.
Use this index in executing the query (perform an index scan using that index).
Throw an exception if it is impossible to use it in query execution.</p>
</td>
      </tr>
      <tr>
        <td id="C1_LiveLinq_IndexingHintAction_Optional">Optional</td>
        <td><p>Create an index for this expression, if such index does not already exist.
Use this index in executing the query, if it is possible.
Do not throw exception if it is impossible to use that index in query execution.</p>
</td>
      </tr>
      <tr>
        <td id="C1_LiveLinq_IndexingHintAction_UseExistingIndex">UseExistingIndex</td>
        <td><p>Check that there exists an index for this expression. If it does not exist, throw an exception.
Use this index in executing the query. Throw an exception if it
is impossible to use this index in query execution.</p>
</td>
      </tr>
    </tbody>
  </table>
  <h3 id="extensionmethods">Extension Methods</h3>
  <div>
      <a class="xref" href="C1.LiveLinq.Hints.Indexed.html#C1_LiveLinq_Hints_Indexed__1___0_">Hints.Indexed&lt;IndexingHintAction&gt;(IndexingHintAction)</a>
  </div>
  <div>
      <a class="xref" href="C1.LiveLinq.Hints.Indexed.html#C1_LiveLinq_Hints_Indexed__1___0_C1_LiveLinq_IndexingHintAction_">Hints.Indexed&lt;IndexingHintAction&gt;(IndexingHintAction, IndexingHintAction)</a>
  </div>
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