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    <div>
     <h3 class="title">
      <a name="performance-schema-instance-tables">
      </a>
      29.12.3 Performance Schema Instance Tables
     </h3>
    </div>
   </div>
  </div>
  <div class="toc">
   <dl class="toc">
    <dt>
     <span class="section">
      <a href="performance-schema-cond-instances-table.html">
       29.12.3.1 The cond_instances Table
      </a>
     </span>
    </dt>
    <dt>
     <span class="section">
      <a href="performance-schema-file-instances-table.html">
       29.12.3.2 The file_instances Table
      </a>
     </span>
    </dt>
    <dt>
     <span class="section">
      <a href="performance-schema-mutex-instances-table.html">
       29.12.3.3 The mutex_instances Table
      </a>
     </span>
    </dt>
    <dt>
     <span class="section">
      <a href="performance-schema-rwlock-instances-table.html">
       29.12.3.4 The rwlock_instances Table
      </a>
     </span>
    </dt>
    <dt>
     <span class="section">
      <a href="performance-schema-socket-instances-table.html">
       29.12.3.5 The socket_instances Table
      </a>
     </span>
    </dt>
   </dl>
  </div>
  <p>
   Instance tables document what types of objects are instrumented.
        They provide event names and explanatory notes or status
        information:
  </p>
  <div class="itemizedlist">
   <ul class="itemizedlist" style="list-style-type: disc; ">
    <li class="listitem">
     <p>
      <a class="link" href="performance-schema-cond-instances-table.html" title="29.12.3.1 The cond_instances Table">
       <code class="literal">
        cond_instances
       </code>
      </a>
      : Condition
            synchronization object instances
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="link" href="performance-schema-file-instances-table.html" title="29.12.3.2 The file_instances Table">
       <code class="literal">
        file_instances
       </code>
      </a>
      : File instances
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="link" href="performance-schema-mutex-instances-table.html" title="29.12.3.3 The mutex_instances Table">
       <code class="literal">
        mutex_instances
       </code>
      </a>
      : Mutex
            synchronization object instances
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="link" href="performance-schema-rwlock-instances-table.html" title="29.12.3.4 The rwlock_instances Table">
       <code class="literal">
        rwlock_instances
       </code>
      </a>
      : Lock
            synchronization object instances
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="link" href="performance-schema-socket-instances-table.html" title="29.12.3.5 The socket_instances Table">
       <code class="literal">
        socket_instances
       </code>
      </a>
      : Active
            connection instances
     </p>
    </li>
   </ul>
  </div>
  <p>
   These tables list instrumented synchronization objects, files,
        and connections. There are three types of synchronization
        objects:
   <code class="literal">
    cond
   </code>
   ,
   <code class="literal">
    mutex
   </code>
   , and
   <code class="literal">
    rwlock
   </code>
   . Each instance table has an
   <code class="literal">
    EVENT_NAME
   </code>
   or
   <code class="literal">
    NAME
   </code>
   column
        to indicate the instrument associated with each row. Instrument
        names may have multiple parts and form a hierarchy, as discussed
        in
   <a class="xref" href="performance-schema-instrument-naming.html" title="29.6 Performance Schema Instrument Naming Conventions">
    Section 29.6, “Performance Schema Instrument Naming Conventions”
   </a>
   .
  </p>
  <p>
   The
   <code class="literal">
    mutex_instances.LOCKED_BY_THREAD_ID
   </code>
   and
   <code class="literal">
    rwlock_instances.WRITE_LOCKED_BY_THREAD_ID
   </code>
   columns are extremely important for investigating performance
        bottlenecks or deadlocks. For examples of how to use them for
        this purpose, see
   <a class="xref" href="performance-schema-examples.html" title="29.19 Using the Performance Schema to Diagnose Problems">
    Section 29.19, “Using the Performance Schema to Diagnose Problems”
   </a>
  </p>
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