docs/api_reference/CXX/dbset_priority.html

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  37             <h2 class="title" style="clear: both"><a id="dbset_priority"></a>Db::set_priority()</h2>
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  41       <pre class="programlisting">#include &lt;db_cxx.h&gt;
  42
  43 int
  44 Db::set_priority(DB_CACHE_PRIORITY priority); </pre>
  45       <p>
  46             Set the cache priority for pages referenced by the
  47             <a class="link" href="db.html" title="Chapter 2.  The Db Handle">Db</a>  handle.
  48     </p>
  49       <p>
  50          The priority of a page biases the replacement algorithm to be more or
  51          less likely to discard a page when space is needed in the buffer pool.
  52          The bias is temporary, and pages will eventually be discarded if they
  53          are not referenced again.  The <code class="methodname">Db::set_priority()</code> method is only
  54          advisory, and does not guarantee pages will be treated in a specific
  55          way.
  56     </p>
  57       <p>
  58          The <code class="methodname">Db::set_priority()</code> method may be called at any time during the
  59          life of the application.
  60     </p>
  61       <p>
  62          The <code class="methodname">Db::set_priority()</code> <span>
  63
  64             <span>
  65                 method either returns a non-zero error value or throws an
  66                 exception that encapsulates a non-zero error value on
  67                 failure, and returns 0 on success.
  68             </span>
  69         </span>
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  71       <div class="sect2" lang="en" xml:lang="en">
  72         <div class="titlepage">
  73           <div>
  74             <div>
  75               <h3 class="title"><a id="idp435208"></a>Parameters</h3>
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  83                 <h4 class="title"><a id="idp434560"></a>priority</h4>
  84               </div>
  85             </div>
  86           </div>
  87           <p>
  88                           The <span class="bold"><strong>priority</strong></span> parameter must be set to
  89                           one of the following values:
  90                      </p>
  91           <div class="itemizedlist">
  92             <ul type="disc">
  93               <li>
  94                 <p><a id="set_priority_DB_PRIORITY_VERY_LOW"></a>
  95                   <code class="literal">DB_PRIORITY_VERY_LOW</code>
  96             </p>
  97                 <p>
  98                  The lowest priority: pages are the most likely to be discarded.
  99             </p>
 100               </li>
 101               <li>
 102                 <p><a id="set_priority_DB_PRIORITY_LOW"></a>
 103                   <code class="literal">DB_PRIORITY_LOW</code>
 104             </p>
 105                 <p>
 106                 The next lowest priority.
 107             </p>
 108               </li>
 109               <li>
 110                 <p><a id="set_priority_DB_PRIORITY_DEFAULT"></a>
 111                   <code class="literal">DB_PRIORITY_DEFAULT</code>
 112             </p>
 113                 <p>
 114                 The default priority.
 115             </p>
 116               </li>
 117               <li>
 118                 <p><a id="set_priority_DB_PRIORITY_HIGH"></a>
 119                   <code class="literal">DB_PRIORITY_HIGH</code>
 120             </p>
 121                 <p>
 122                 The next highest priority.
 123             </p>
 124               </li>
 125               <li>
 126                 <p><a id="set_priority_DB_PRIORITY_VERY_HIGH"></a>
 127                   <code class="literal">DB_PRIORITY_VERY_HIGH</code>
 128             </p>
 129                 <p>
 130                  The highest priority: pages are the least likely to be discarded.
 131             </p>
 132               </li>
 133             </ul>
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