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  <div class="titlepage">
   <div>
    <div>
     <h3 class="title">
      <a name="performance-schema-ndb-cluster-tables">
      </a>
      29.12.12 Performance Schema NDB Cluster Tables
     </h3>
    </div>
   </div>
  </div>
  <div class="toc">
   <dl class="toc">
    <dt>
     <span class="section">
      <a href="performance-schema-ndb-sync-pending-objects-table.html">
       29.12.12.1 The ndb_sync_pending_objects Table
      </a>
     </span>
    </dt>
    <dt>
     <span class="section">
      <a href="performance-schema-ndb-sync-excluded-objects-table.html">
       29.12.12.2 The ndb_sync_excluded_objects Table
      </a>
     </span>
    </dt>
   </dl>
  </div>
  <p>
   The following table shows all Performance Schema tables relating
        to the
   <a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
    <code class="literal">
     NDBCLUSTER
    </code>
   </a>
   storage engine.
  </p>
  <div class="table">
   <a name="idm46045070664224">
   </a>
   <p class="title">
    <b>
     Table 29.3 Performance Schema NDB Tables
    </b>
   </p>
   <div class="table-contents">
    <table frame="box" rules="all" summary="A reference that lists all Performance Schema tables relating to NDB Cluster.">
     <colgroup>
      <col style="width: 28%"/>
      <col style="width: 71%"/>
     </colgroup>
     <thead>
      <tr>
       <th>
        Table Name
       </th>
       <th>
        Description
       </th>
      </tr>
     </thead>
     <tbody>
      <tr>
       <td>
        <a class="link" href="performance-schema-ndb-sync-excluded-objects-table.html" title="29.12.12.2 The ndb_sync_excluded_objects Table">
         <code class="literal">
          ndb_sync_excluded_objects
         </code>
        </a>
       </td>
       <td>
        NDB objects which cannot be synchronized
       </td>
      </tr>
      <tr>
       <td>
        <a class="link" href="performance-schema-ndb-sync-pending-objects-table.html" title="29.12.12.1 The ndb_sync_pending_objects Table">
         <code class="literal">
          ndb_sync_pending_objects
         </code>
        </a>
       </td>
       <td>
        NDB objects waiting for synchronization
       </td>
      </tr>
     </tbody>
    </table>
   </div>
  </div>
  <br class="table-break"/>
  <p>
   Automatic synchronization in
   <a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
    <code class="literal">
     NDB
    </code>
   </a>
   attempts to detect and synchronize automatically all mismatches
        in metadata between the NDB Cluster's internal dictionary
        and the MySQL Server's datadictionary. This is done by
        default in the background at regular intervals as determined by
        the
   <a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_metadata_check_interval">
    <code class="literal">
     ndb_metadata_check_interval
    </code>
   </a>
   system variable, unless disabled using
   <a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_metadata_check">
    <code class="literal">
     ndb_metadata_check
    </code>
   </a>
   or
        overridden by setting
   <a class="link" href="mysql-cluster-options-variables.html#sysvar_ndb_metadata_sync">
    <code class="literal">
     ndb_metadata_sync
    </code>
   </a>
   .
  </p>
  <p>
   Information about the current state of automatic synchronization
        is exposed by a MySQL server acting as an SQL node in an NDB
        Cluster in these two Performance Schema tables:
  </p>
  <div class="itemizedlist">
   <ul class="itemizedlist" style="list-style-type: disc; ">
    <li class="listitem">
     <p>
      <a class="link" href="performance-schema-ndb-sync-pending-objects-table.html" title="29.12.12.1 The ndb_sync_pending_objects Table">
       <code class="literal">
        ndb_sync_pending_objects
       </code>
      </a>
      :
            Displays information about
      <a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
       <code class="literal">
        NDB
       </code>
      </a>
      database objects for which mismatches have been detected
            between the
      <code class="literal">
       NDB
      </code>
      dictionary and the MySQL
            data dictionary. When attempting to synchronize such
            objects,
      <a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
       <code class="literal">
        NDB
       </code>
      </a>
      removes the object
            from the queue awaiting synchronization, and from this
            table, and tries to reconcile the mismatch. If
            synchronization of the object fails due to a temporary
            error, it is picked up and added back to the queue (and to
            this table) the next time
      <code class="literal">
       NDB
      </code>
      performs
            mismatch detection; if the attempts fails due a permanent
            error, the object is added to the
      <a class="link" href="performance-schema-ndb-sync-excluded-objects-table.html" title="29.12.12.2 The ndb_sync_excluded_objects Table">
       <code class="literal">
        ndb_sync_excluded_objects
       </code>
      </a>
      table.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="link" href="performance-schema-ndb-sync-excluded-objects-table.html" title="29.12.12.2 The ndb_sync_excluded_objects Table">
       <code class="literal">
        ndb_sync_excluded_objects
       </code>
      </a>
      :
            Shows information about
      <a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
       <code class="literal">
        NDB
       </code>
      </a>
      database objects for which automatic synchronization has
            failed due to permanent errors resulting from mismatches
            which cannot be reconciled without manual intervention;
            these objects are blocklisted and not considered again for
            mismatch detection until this has been done.
     </p>
    </li>
   </ul>
  </div>
  <p>
   The
   <a class="link" href="performance-schema-ndb-sync-pending-objects-table.html" title="29.12.12.1 The ndb_sync_pending_objects Table">
    <code class="literal">
     ndb_sync_pending_objects
    </code>
   </a>
   and
   <a class="link" href="performance-schema-ndb-sync-excluded-objects-table.html" title="29.12.12.2 The ndb_sync_excluded_objects Table">
    <code class="literal">
     ndb_sync_excluded_objects
    </code>
   </a>
   tables
        are present only if MySQL has support enabled for the
   <a class="link" href="mysql-cluster.html" title="Chapter 25 MySQL NDB Cluster 8.4">
    <code class="literal">
     NDBCLUSTER
    </code>
   </a>
   storage engine.
  </p>
  <p>
   These tables are described in more detail in the following two
        sections.
  </p>
 </div>
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