<div id="docs-body">
 <div class="section">
  <div class="titlepage">
   <div>
    <div>
     <h4 class="title">
      <a name="innodb-preload-buffer-pool">
      </a>
      17.8.3.6 Saving and Restoring the Buffer Pool State
     </h4>
    </div>
   </div>
  </div>
  <a class="indexterm" name="idm46045162979136">
  </a>
  <a class="indexterm" name="idm46045162978064">
  </a>
  <p>
   To reduce the
   <a class="link" href="glossary.html#glos_warm_up" title="warm up">
    warmup
   </a>
   period
        after restarting the server,
   <code class="literal">
    InnoDB
   </code>
   saves a
        percentage of the most recently used pages for each buffer pool
        at server shutdown and restores these pages at server startup.
        The percentage of recently used pages that is stored is defined
        by the
   <a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_dump_pct">
    <code class="literal">
     innodb_buffer_pool_dump_pct
    </code>
   </a>
   configuration option.
  </p>
  <p>
   After restarting a busy server, there is typically a warmup
        period with steadily increasing throughput, as disk pages that
        were in the buffer pool are brought back into memory (as the
        same data is queried, updated, and so on). The ability to
        restore the buffer pool at startup shortens the warmup period by
        reloading disk pages that were in the buffer pool before the
        restart rather than waiting for DML operations to access
        corresponding rows. Also, I/O requests can be performed in large
        batches, making the overall I/O faster. Page loading happens in
        the background, and does not delay database startup.
  </p>
  <p>
   In addition to saving the buffer pool state at shutdown and
        restoring it at startup, you can save and restore the buffer
        pool state at any time, while the server is running. For
        example, you can save the state of the buffer pool after
        reaching a stable throughput under a steady workload. You could
        also restore the previous buffer pool state after running
        reports or maintenance jobs that bring data pages into the
        buffer pool that are only requited for those operations, or
        after running some other non-typical workload.
  </p>
  <p>
   Even though a buffer pool can be many gigabytes in size, the
        buffer pool data that
   <code class="literal">
    InnoDB
   </code>
   saves to disk is
        tiny by comparison. Only tablespace IDs and page IDs necessary
        to locate the appropriate pages are saved to disk. This
        information is derived from the
   <a class="link" href="information-schema-innodb-buffer-page-lru-table.html" title="28.4.3 The INFORMATION_SCHEMA INNODB_BUFFER_PAGE_LRU Table">
    <code class="literal">
     INNODB_BUFFER_PAGE_LRU
    </code>
   </a>
   <code class="literal">
    INFORMATION_SCHEMA
   </code>
   table. By default,
        tablespace ID and page ID data is saved in a file named
   <code class="filename">
    ib_buffer_pool
   </code>
   , which is saved to the
   <code class="literal">
    InnoDB
   </code>
   data directory. The file name and
        location can be modified using the
   <a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_filename">
    <code class="literal">
     innodb_buffer_pool_filename
    </code>
   </a>
   configuration parameter.
  </p>
  <p>
   Because data is cached in and aged out of the buffer pool as it
        is with regular database operations, there is no problem if the
        disk pages are recently updated, or if a DML operation involves
        data that has not yet been loaded. The loading mechanism skips
        requested pages that no longer exist.
  </p>
  <p>
   The underlying mechanism involves a background thread that is
        dispatched to perform the dump and load operations.
  </p>
  <p>
   Disk pages from compressed tables are loaded into the buffer
        pool in their compressed form. Pages are uncompressed as usual
        when page contents are accessed during DML operations. Because
        uncompressing pages is a CPU-intensive process, it is more
        efficient for concurrency to perform the operation in a
        connection thread rather than in the single thread that performs
        the buffer pool restore operation.
  </p>
  <p>
   Operations related to saving and restoring the buffer pool state
        are described in the following topics:
  </p>
  <div class="itemizedlist">
   <ul class="itemizedlist" style="list-style-type: disc; ">
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-preload-buffer-pool.html#innodb-preload-buffer-pool-dump-pct" title="Configuring the Dump Percentage for Buffer Pool Pages">
       Configuring the Dump Percentage for Buffer Pool Pages
      </a>
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-preload-buffer-pool.html#innodb-preload-buffer-pool-offline" title="Saving the Buffer Pool State at Shutdown and Restoring it at Startup">
       Saving the Buffer Pool State at Shutdown and Restoring it at Startup
      </a>
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-preload-buffer-pool.html#innodb-preload-buffer-pool-online" title="Saving and Restoring the Buffer Pool State Online">
       Saving and Restoring the Buffer Pool State Online
      </a>
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-preload-buffer-pool.html#innodb-preload-buffer-pool-dump-progress" title="Displaying Buffer Pool Dump Progress">
       Displaying Buffer Pool Dump Progress
      </a>
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-preload-buffer-pool.html#innodb-preload-buffer-pool-load-progress" title="Displaying Buffer Pool Load Progress">
       Displaying Buffer Pool Load Progress
      </a>
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-preload-buffer-pool.html#innodb-preload-buffer-pool-abort-load" title="Aborting a Buffer Pool Load Operation">
       Aborting a Buffer Pool Load Operation
      </a>
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-preload-buffer-pool.html#monitor-buffer-pool-load-performance-schema" title="Monitoring Buffer Pool Load Progress Using Performance Schema">
       Monitoring Buffer Pool Load Progress Using Performance Schema
      </a>
     </p>
    </li>
   </ul>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h5 class="title">
       <a name="innodb-preload-buffer-pool-dump-pct">
       </a>
       Configuring the Dump Percentage for Buffer Pool Pages
      </h5>
     </div>
    </div>
   </div>
   <p>
    Before dumping pages from the buffer pool, you can configure
          the percentage of most-recently-used buffer pool pages that
          you want to dump by setting the
    <a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_dump_pct">
     <code class="literal">
      innodb_buffer_pool_dump_pct
     </code>
    </a>
    option. If you plan to dump buffer pool pages while the server
          is running, you can configure the option dynamically:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa67757593"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SET</span> <span class="token keyword">GLOBAL</span> innodb_buffer_pool_dump_pct<span class="token operator">=</span><span class="token number">40</span><span class="token punctuation">;</span></code></pre>
   </div>
   <p>
    If you plan to dump buffer pool pages at server shutdown, set
    <a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_dump_pct">
     <code class="literal">
      innodb_buffer_pool_dump_pct
     </code>
    </a>
    in your configuration file.
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-ini"><div class="docs-select-all right" id="sa88861208"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-ini"><span class="token selector">[mysqld]</span>
<span class="token constant">innodb_buffer_pool_dump_pct</span><span class="token attr-value"><span class="token punctuation">=</span>40</span></code></pre>
   </div>
   <p>
    The
    <a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_dump_pct">
     <code class="literal">
      innodb_buffer_pool_dump_pct
     </code>
    </a>
    default value is 25 (dump 25% of most-recently-used pages).
   </p>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h5 class="title">
       <a name="innodb-preload-buffer-pool-offline">
       </a>
       Saving the Buffer Pool State at Shutdown and Restoring it at Startup
      </h5>
     </div>
    </div>
   </div>
   <p>
    To save the state of the buffer pool at server shutdown, issue
          the following statement prior to shutting down the server:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa46760145"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SET</span> <span class="token keyword">GLOBAL</span> innodb_buffer_pool_dump_at_shutdown<span class="token operator">=</span><span class="token keyword">ON</span><span class="token punctuation">;</span></code></pre>
   </div>
   <p>
    <a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_dump_at_shutdown">
     <code class="literal">
      innodb_buffer_pool_dump_at_shutdown
     </code>
    </a>
    is enabled by default.
   </p>
   <p>
    To restore the buffer pool state at server startup, specify
          the
    <code class="literal">
     --innodb-buffer-pool-load-at-startup
    </code>
    option when starting the server:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa92818934"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-terminal">mysqld <span class="token constant">--innodb-buffer-pool-load-at-startup</span><span class="token attr-value"><span class="token punctuation">=</span>ON;</span></code></pre>
   </div>
   <p>
    <a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_load_at_startup">
     <code class="literal">
      innodb_buffer_pool_load_at_startup
     </code>
    </a>
    is enabled by default.
   </p>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h5 class="title">
       <a name="innodb-preload-buffer-pool-online">
       </a>
       Saving and Restoring the Buffer Pool State Online
      </h5>
     </div>
    </div>
   </div>
   <p>
    To save the state of the buffer pool while MySQL server is
          running, issue the following statement:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa58846415"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SET</span> <span class="token keyword">GLOBAL</span> innodb_buffer_pool_dump_now<span class="token operator">=</span><span class="token keyword">ON</span><span class="token punctuation">;</span></code></pre>
   </div>
   <p>
    To restore the buffer pool state while MySQL is running, issue
          the following statement:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa2401883"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SET</span> <span class="token keyword">GLOBAL</span> innodb_buffer_pool_load_now<span class="token operator">=</span><span class="token keyword">ON</span><span class="token punctuation">;</span></code></pre>
   </div>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h5 class="title">
       <a name="innodb-preload-buffer-pool-dump-progress">
       </a>
       Displaying Buffer Pool Dump Progress
      </h5>
     </div>
    </div>
   </div>
   <p>
    To display progress when saving the buffer pool state to disk,
          issue the following statement:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa16007611"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SHOW</span> <span class="token keyword">STATUS</span> <span class="token operator">LIKE</span> <span class="token string">'Innodb_buffer_pool_dump_status'</span><span class="token punctuation">;</span></code></pre>
   </div>
   <p>
    If the operation has not yet started,
    <span class="quote">
     “
     <span class="quote">
      not
          started
     </span>
     ”
    </span>
    is returned. If the operation is complete, the
          completion time is printed (e.g. Finished at 110505 12:18:02).
          If the operation is in progress, status information is
          provided (e.g. Dumping buffer pool 5/7, page 237/2873).
   </p>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h5 class="title">
       <a name="innodb-preload-buffer-pool-load-progress">
       </a>
       Displaying Buffer Pool Load Progress
      </h5>
     </div>
    </div>
   </div>
   <p>
    To display progress when loading the buffer pool, issue the
          following statement:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa27455180"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SHOW</span> <span class="token keyword">STATUS</span> <span class="token operator">LIKE</span> <span class="token string">'Innodb_buffer_pool_load_status'</span><span class="token punctuation">;</span></code></pre>
   </div>
   <p>
    If the operation has not yet started,
    <span class="quote">
     “
     <span class="quote">
      not
          started
     </span>
     ”
    </span>
    is returned. If the operation is complete, the
          completion time is printed (e.g. Finished at 110505 12:23:24).
          If the operation is in progress, status information is
          provided (e.g. Loaded 123/22301 pages).
   </p>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h5 class="title">
       <a name="innodb-preload-buffer-pool-abort-load">
       </a>
       Aborting a Buffer Pool Load Operation
      </h5>
     </div>
    </div>
   </div>
   <p>
    To abort a buffer pool load operation, issue the following
          statement:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa69111799"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token keyword">SET</span> <span class="token keyword">GLOBAL</span> innodb_buffer_pool_load_abort<span class="token operator">=</span><span class="token keyword">ON</span><span class="token punctuation">;</span></code></pre>
   </div>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h5 class="title">
       <a name="monitor-buffer-pool-load-performance-schema">
       </a>
       Monitoring Buffer Pool Load Progress Using Performance Schema
      </h5>
     </div>
    </div>
   </div>
   <a class="indexterm" name="idm46045162921280">
   </a>
   <a class="indexterm" name="idm46045162919792">
   </a>
   <p>
    You can monitor buffer pool load progress using
    <a class="link" href="performance-schema.html" title="Chapter 29 MySQL Performance Schema">
     Performance Schema
    </a>
    .
   </p>
   <p>
    The following example demonstrates how to enable the
    <code class="literal">
     stage/innodb/buffer pool load
    </code>
    stage event
          instrument and related consumer tables to monitor buffer pool
          load progress.
   </p>
   <p>
    For information about buffer pool dump and load procedures
          used in this example, see
    <a class="xref" href="innodb-preload-buffer-pool.html" title="17.8.3.6 Saving and Restoring the Buffer Pool State">
     Section 17.8.3.6, “Saving and Restoring the Buffer Pool State”
    </a>
    . For information
          about Performance Schema stage event instruments and related
          consumers, see
    <a class="xref" href="performance-schema-stage-tables.html" title="29.12.5 Performance Schema Stage Event Tables">
     Section 29.12.5, “Performance Schema Stage Event Tables”
    </a>
    .
   </p>
   <div class="orderedlist">
    <ol class="orderedlist" type="1">
     <li class="listitem">
      <p>
       Enable the
       <code class="literal">
        stage/innodb/buffer pool
              load
       </code>
       instrument:
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa50867671"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">UPDATE</span> performance_schema<span class="token punctuation">.</span>setup_instruments <span class="token keyword">SET</span> ENABLED <span class="token operator">=</span> <span class="token string">'YES'</span> 
       <span class="token keyword">WHERE</span> <span class="token keyword">NAME</span> <span class="token operator">LIKE</span> <span class="token string">'stage/innodb/buffer%'</span><span class="token punctuation">;</span></code></pre>
      </div>
     </li>
     <li class="listitem">
      <p>
       Enable the stage event consumer tables, which include
       <a class="link" href="performance-schema-events-stages-current-table.html" title="29.12.5.1 The events_stages_current Table">
        <code class="literal">
         events_stages_current
        </code>
       </a>
       ,
       <a class="link" href="performance-schema-events-stages-history-table.html" title="29.12.5.2 The events_stages_history Table">
        <code class="literal">
         events_stages_history
        </code>
       </a>
       , and
       <a class="link" href="performance-schema-events-stages-history-long-table.html" title="29.12.5.3 The events_stages_history_long Table">
        <code class="literal">
         events_stages_history_long
        </code>
       </a>
       .
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa24683965"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">UPDATE</span> performance_schema<span class="token punctuation">.</span>setup_consumers <span class="token keyword">SET</span> ENABLED <span class="token operator">=</span> <span class="token string">'YES'</span> 
       <span class="token keyword">WHERE</span> <span class="token keyword">NAME</span> <span class="token operator">LIKE</span> <span class="token string">'%stages%'</span><span class="token punctuation">;</span></code></pre>
      </div>
     </li>
     <li class="listitem">
      <p>
       Dump the current buffer pool state by enabling
       <a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_dump_now">
        <code class="literal">
         innodb_buffer_pool_dump_now
        </code>
       </a>
       .
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa97446219"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">SET</span> <span class="token keyword">GLOBAL</span> innodb_buffer_pool_dump_now<span class="token operator">=</span><span class="token keyword">ON</span><span class="token punctuation">;</span></code></pre>
      </div>
     </li>
     <li class="listitem">
      <p>
       Check the buffer pool dump status to ensure that the
              operation has completed.
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa7788025"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">SHOW</span> <span class="token keyword">STATUS</span> <span class="token operator">LIKE</span> <span class="token string">'Innodb_buffer_pool_dump_status'</span>\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
Variable_name<span class="token punctuation">:</span> Innodb_buffer_pool_dump_status
        Value<span class="token punctuation">:</span> Buffer pool(s) dump completed at 150202 16<span class="token punctuation">:</span>38<span class="token punctuation">:</span>58</span></code></pre>
      </div>
     </li>
     <li class="listitem">
      <p>
       Load the buffer pool by enabling
       <a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_load_now">
        <code class="literal">
         innodb_buffer_pool_load_now
        </code>
       </a>
       :
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa59666568"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">SET</span> <span class="token keyword">GLOBAL</span> innodb_buffer_pool_load_now<span class="token operator">=</span><span class="token keyword">ON</span><span class="token punctuation">;</span></code></pre>
      </div>
     </li>
     <li class="listitem">
      <p>
       Check the current status of the buffer pool load operation
              by querying the Performance Schema
       <a class="link" href="performance-schema-events-stages-current-table.html" title="29.12.5.1 The events_stages_current Table">
        <code class="literal">
         events_stages_current
        </code>
       </a>
       table.
              The
       <code class="literal">
        WORK_COMPLETED
       </code>
       column shows the
              number of buffer pool pages loaded. The
       <code class="literal">
        WORK_ESTIMATED
       </code>
       column provides an
              estimate of the remaining work, in pages.
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa86219923"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">SELECT</span> EVENT_NAME<span class="token punctuation">,</span> WORK_COMPLETED<span class="token punctuation">,</span> WORK_ESTIMATED
       <span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>events_stages_current<span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> EVENT_NAME                    <span class="token punctuation">|</span> WORK_COMPLETED <span class="token punctuation">|</span> WORK_ESTIMATED <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> stage/innodb/buffer pool load <span class="token punctuation">|</span>           5353 <span class="token punctuation">|</span>           7167 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
      </div>
      <p>
       The
       <a class="link" href="performance-schema-events-stages-current-table.html" title="29.12.5.1 The events_stages_current Table">
        <code class="literal">
         events_stages_current
        </code>
       </a>
       table returns an empty set if the buffer pool load
              operation has completed. In this case, you can check the
       <a class="link" href="performance-schema-events-stages-history-table.html" title="29.12.5.2 The events_stages_history Table">
        <code class="literal">
         events_stages_history
        </code>
       </a>
       table
              to view data for the completed event. For example:
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa58437167"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">SELECT</span> EVENT_NAME<span class="token punctuation">,</span> WORK_COMPLETED<span class="token punctuation">,</span> WORK_ESTIMATED 
       <span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>events_stages_history<span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> EVENT_NAME                    <span class="token punctuation">|</span> WORK_COMPLETED <span class="token punctuation">|</span> WORK_ESTIMATED <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> stage/innodb/buffer pool load <span class="token punctuation">|</span>           7167 <span class="token punctuation">|</span>           7167 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
      </div>
     </li>
    </ol>
   </div>
   <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
    <div class="admon-title">
     Note
    </div>
    <p>
     You can also monitor buffer pool load progress using
            Performance Schema when loading the buffer pool at startup
            using
     <a class="link" href="innodb-parameters.html#sysvar_innodb_buffer_pool_load_at_startup">
      <code class="literal">
       innodb_buffer_pool_load_at_startup
      </code>
     </a>
     .
            In this case, the
     <code class="literal">
      stage/innodb/buffer pool
            load
     </code>
     instrument and related consumers must be
            enabled at startup. For more information, see
     <a class="xref" href="performance-schema-startup-configuration.html" title="29.3 Performance Schema Startup Configuration">
      Section 29.3, “Performance Schema Startup Configuration”
     </a>
     .
    </p>
   </div>
  </div>
 </div>
 <br/>
</div>
