<section>
 <h1 class="contains-headerlink leafygreen-ui-41fr9s" weight="medium">
  cursor.allowDiskUse()
  <a class="headerlink leafygreen-ui-1kepx47" href="#cursor.allowdiskuse--" title="Permalink to this heading">
   <svg aria-label="Link Icon" class="leafygreen-ui-a30zj9" fill="none" height="12" role="img" viewbox="0 0 16 16" width="12" xmlns="http://www.w3.org/2000/svg">
    <path d="M6.039 9.953a3.596 3.596 0 0 1-.327-.38l1.45-1.445a1.553 1.553 0 0 0 2.496.423l2.885-2.87a1.57 1.57 0 0 0 .01-2.213 1.553 1.553 0 0 0-2.203-.01l-.379.377A.995.995 0 0 1 8.56 3.83a1.005 1.005 0 0 1 .006-1.418l.38-.377a3.542 3.542 0 0 1 5.024.023 3.58 3.58 0 0 1-.022 5.047l-2.884 2.871a3.542 3.542 0 0 1-5.025-.022Z" fill="currentColor">
    </path>
    <path d="M9.961 6.047c.12.12.228.248.327.38l-1.45 1.445a1.553 1.553 0 0 0-2.496-.423l-2.885 2.87a1.57 1.57 0 0 0-.01 2.213 1.553 1.553 0 0 0 2.203.01l.379-.377a.995.995 0 0 1 1.411.006 1.005 1.005 0 0 1-.006 1.418l-.38.377a3.542 3.542 0 0 1-5.024-.023 3.58 3.58 0 0 1 .022-5.047l2.884-2.871a3.542 3.542 0 0 1 5.025.022Z" fill="currentColor">
    </path>
   </svg>
   <div class="css-1btu0w3 evvkmar0" id="cursor.allowdiskuse--">
   </div>
  </a>
 </h1>
 <div class="leafygreen-ui-a5yxub">
  <p class="css-1cmx2d4 ef7gu8j0">
   On this page
  </p>
  <ul class="css-1qb0mst ef7gu8j1">
   <li class="leafygreen-ui-1e7a0ei">
    <a class="lg-ui-0001 leafygreen-ui-e98ikf" href="#definition" target="_self">
     <span>
      Definition
     </span>
    </a>
   </li>
   <li class="leafygreen-ui-1jqtqlb">
    <a class="lg-ui-0001 leafygreen-ui-cpmeq5" href="#behavior" target="_self">
     <span>
      Behavior
     </span>
    </a>
   </li>
   <li class="leafygreen-ui-1jqtqlb">
    <a class="lg-ui-0001 leafygreen-ui-cpmeq5" href="#example" target="_self">
     <span>
      Example
     </span>
    </a>
   </li>
  </ul>
 </div>
 <section>
  <h2 class="contains-headerlink leafygreen-ui-19f71ei" weight="medium">
   Definition
   <a class="headerlink leafygreen-ui-1kepx47" href="#definition" title="Permalink to this heading">
    <svg aria-label="Link Icon" class="leafygreen-ui-a30zj9" fill="none" height="12" role="img" viewbox="0 0 16 16" width="12" xmlns="http://www.w3.org/2000/svg">
     <path d="M6.039 9.953a3.596 3.596 0 0 1-.327-.38l1.45-1.445a1.553 1.553 0 0 0 2.496.423l2.885-2.87a1.57 1.57 0 0 0 .01-2.213 1.553 1.553 0 0 0-2.203-.01l-.379.377A.995.995 0 0 1 8.56 3.83a1.005 1.005 0 0 1 .006-1.418l.38-.377a3.542 3.542 0 0 1 5.024.023 3.58 3.58 0 0 1-.022 5.047l-2.884 2.871a3.542 3.542 0 0 1-5.025-.022Z" fill="currentColor">
     </path>
     <path d="M9.961 6.047c.12.12.228.248.327.38l-1.45 1.445a1.553 1.553 0 0 0-2.496-.423l-2.885 2.87a1.57 1.57 0 0 0-.01 2.213 1.553 1.553 0 0 0 2.203.01l.379-.377a.995.995 0 0 1 1.411.006 1.005 1.005 0 0 1-.006 1.418l-.38.377a3.542 3.542 0 0 1-5.024-.023 3.58 3.58 0 0 1 .022-5.047l2.884-2.871a3.542 3.542 0 0 1 5.025.022Z" fill="currentColor">
     </path>
    </svg>
    <div class="css-1btu0w3 evvkmar0" id="definition">
    </div>
   </a>
  </h2>
  <dl class="method">
   <dt>
    <code class="leafygreen-ui-1l06pbn">
     cursor.allowDiskUse()
    </code>
    <a class="headerlink leafygreen-ui-1kepx47" href="#mongodb-method-cursor.allowDiskUse" title="Permalink to this definition">
     <svg aria-label="Link Icon" class="leafygreen-ui-a30zj9" fill="none" height="12" role="img" viewbox="0 0 16 16" width="12" xmlns="http://www.w3.org/2000/svg">
      <path d="M6.039 9.953a3.596 3.596 0 0 1-.327-.38l1.45-1.445a1.553 1.553 0 0 0 2.496.423l2.885-2.87a1.57 1.57 0 0 0 .01-2.213 1.553 1.553 0 0 0-2.203-.01l-.379.377A.995.995 0 0 1 8.56 3.83a1.005 1.005 0 0 1 .006-1.418l.38-.377a3.542 3.542 0 0 1 5.024.023 3.58 3.58 0 0 1-.022 5.047l-2.884 2.871a3.542 3.542 0 0 1-5.025-.022Z" fill="currentColor">
      </path>
      <path d="M9.961 6.047c.12.12.228.248.327.38l-1.45 1.445a1.553 1.553 0 0 0-2.496-.423l-2.885 2.87a1.57 1.57 0 0 0-.01 2.213 1.553 1.553 0 0 0 2.203.01l.379-.377a.995.995 0 0 1 1.411.006 1.005 1.005 0 0 1-.006 1.418l-.38.377a3.542 3.542 0 0 1-5.024-.023 3.58 3.58 0 0 1 .022-5.047l2.884-2.871a3.542 3.542 0 0 1 5.025.022Z" fill="currentColor">
      </path>
     </svg>
     <div class="css-1btu0w3 evvkmar0" id="mongodb-method-cursor.allowDiskUse">
     </div>
    </a>
   </dt>
   <dd>
    <div class="leafygreen-ui-85da11" role="note">
     <h2 class="leafygreen-ui-1ac4g5h">
      Important
     </h2>
     <h3 class="leafygreen-ui-144d5kf">
      <strong>
       mongosh Method
      </strong>
     </h3>
     <div class="leafygreen-ui-9mycqc">
      <p class="leafygreen-ui-1kp3ins">
       This page documents a
       <a class="lg-ui-0001 leafygreen-ui-fgcsv5" href="https://www.mongodb.com/docs/mongodb-shell/#mongodb-binary-bin.mongosh" target="_self">
        <span>
         <code class="leafygreen-ui-1l06pbn">
          mongosh
         </code>
        </span>
       </a>
       method. This is
       <em>
        not
       </em>
       the documentation for a language-specific driver, such as Node.js.
      </p>
      <p class="leafygreen-ui-1kp3ins">
       For MongoDB API drivers, refer to the language-specific
       <a class="lg-ui-0001 leafygreen-ui-fgcsv5" href="https://www.mongodb.com/docs/drivers/" target="_self">
        <span>
         MongoDB driver documentation
         <!-- -->
         .
        </span>
       </a>
      </p>
     </div>
    </div>
    <p class="leafygreen-ui-1kp3ins">
     Use
     <a class="lg-ui-0001 leafygreen-ui-fgcsv5" href="#mongodb-method-cursor.allowDiskUse" target="_self">
      <span>
       <code class="leafygreen-ui-1l06pbn">
        allowDiskUse()
       </code>
      </span>
     </a>
     to either allow or prohibit
writing temporary files on disk when a pipeline stage exceeds
the 100 megabyte limit. Starting in MongoDB 6.0, operations that
require greater than 100 megabytes of memory automatically write
data to temporary files by default.
    </p>
    <p class="leafygreen-ui-1kp3ins">
     <a class="lg-ui-0001 leafygreen-ui-fgcsv5" href="#mongodb-method-cursor.allowDiskUse" target="_self">
      <span>
       <code class="leafygreen-ui-1l06pbn">
        allowDiskUse()
       </code>
      </span>
     </a>
     has the following form:
    </p>
    <script class="structured_data" type="application/ld+json">
     {"@context":"https://schema.org","@type":"SoftwareSourceCode","codeSampleType":"code snippet","text":"db.collection.find(&lt;match&gt;).sort(&lt;sort&gt;).allowDiskUse()","programmingLanguage":"JavaScript"}
    </script>
    <div class="css-16lmvu9">
     <div class="leafygreen-ui-196mwvg">
      <div class="leafygreen-ui-1b1bvay">
       <pre class="leafygreen-ui-1q4bxgx" tabindex="0"><code class="lg-highlight-hljs-light javascript leafygreen-ui-9ybzas"><table class="leafygreen-ui-1tr4g10"><tbody><tr class=""><td class="leafygreen-ui-7razhx">db.<span class="lg-highlight-property">collection</span>.<span class="lg-highlight-title lg-highlight-function">find</span>(&lt;<!-- -->match<!-- -->&gt;<!-- -->).<span class="lg-highlight-title lg-highlight-function">sort</span>(&lt;<!-- -->sort<!-- -->&gt;<!-- -->).<span class="lg-highlight-title lg-highlight-function">allowDiskUse</span>(<!-- -->)</td></tr></tbody></table></code></pre>
       <div class="leafygreen-ui-1bqcprk" data-testid="leafygreen-code-panel">
        <button aria-disabled="false" aria-label="Copy" class="leafygreen-ui-1c6zwke" data-testid="code_copy-button" tabindex="0">
         <div class="leafygreen-ui-xhlipt">
          <svg aria-label="Copy Icon" class="leafygreen-ui-1st74h4" height="16" role="img" viewbox="0 0 16 16" width="16">
           <path clip-rule="evenodd" d="M1 5.71428V10.2857C1 11.2325 1.76751 12 2.71429 12H5.75V7.10957C5.75 6.54414 5.97724 6.00244 6.38065 5.60623L8.67403 3.35381C8.77447 3.25516 8.88376 3.16757 9 3.09182V2.71429C9 1.76751 8.23249 1 7.28571 1H5.8V4.42857C5.8 5.13865 5.22437 5.71428 4.51429 5.71428H1ZM9 4.78571L7.25654 6.49804C7.24689 6.50752 7.23749 6.5172 7.22834 6.52708C7.22208 6.53383 7.21594 6.54068 7.20991 6.54762C7.07504 6.70295 7 6.90234 7 7.10957V7.79762H9H10.0095C10.4829 7.79762 10.8667 7.41386 10.8667 6.94047V4H10.1505C9.92587 4 9.7102 4.0882 9.54992 4.24562L9 4.78571ZM4.86667 1H4.15053C3.92587 1 3.7102 1.0882 3.54992 1.24562L1.25654 3.49804C1.09244 3.65921 1 3.87957 1 4.10957V4.79762H4.00952C4.48291 4.79762 4.86667 4.41386 4.86667 3.94047V1ZM7 12V8.71428H9H10.5143C11.2244 8.71428 11.8 8.13865 11.8 7.42857V4H13.2857C14.2325 4 15 4.76751 15 5.71429V13.2857C15 14.2325 14.2325 15 13.2857 15H8.71429C7.76751 15 7 14.2325 7 13.2857V12Z" fill="currentColor" fill-rule="evenodd">
           </path>
          </svg>
         </div>
        </button>
       </div>
      </div>
     </div>
    </div>
   </dd>
  </dl>
  <p class="leafygreen-ui-1kp3ins">
   See
   <a class="leafygreen-ui-tqgtui" href="/docs/manual/reference/method/cursor.sort/#std-label-sort-index-use">
    Sort and Index Use
   </a>
   for more information on blocking sort
operations.
  </p>
 </section>
 <section>
  <h2 class="contains-headerlink leafygreen-ui-19f71ei" weight="medium">
   Behavior
   <a class="headerlink leafygreen-ui-1kepx47" href="#behavior" title="Permalink to this heading">
    <svg aria-label="Link Icon" class="leafygreen-ui-a30zj9" fill="none" height="12" role="img" viewbox="0 0 16 16" width="12" xmlns="http://www.w3.org/2000/svg">
     <path d="M6.039 9.953a3.596 3.596 0 0 1-.327-.38l1.45-1.445a1.553 1.553 0 0 0 2.496.423l2.885-2.87a1.57 1.57 0 0 0 .01-2.213 1.553 1.553 0 0 0-2.203-.01l-.379.377A.995.995 0 0 1 8.56 3.83a1.005 1.005 0 0 1 .006-1.418l.38-.377a3.542 3.542 0 0 1 5.024.023 3.58 3.58 0 0 1-.022 5.047l-2.884 2.871a3.542 3.542 0 0 1-5.025-.022Z" fill="currentColor">
     </path>
     <path d="M9.961 6.047c.12.12.228.248.327.38l-1.45 1.445a1.553 1.553 0 0 0-2.496-.423l-2.885 2.87a1.57 1.57 0 0 0-.01 2.213 1.553 1.553 0 0 0 2.203.01l.379-.377a.995.995 0 0 1 1.411.006 1.005 1.005 0 0 1-.006 1.418l-.38.377a3.542 3.542 0 0 1-5.024-.023 3.58 3.58 0 0 1 .022-5.047l2.884-2.871a3.542 3.542 0 0 1 5.025.022Z" fill="currentColor">
     </path>
    </svg>
    <div class="css-1btu0w3 evvkmar0" id="behavior">
    </div>
   </a>
  </h2>
  <section>
   <h3 class="contains-headerlink leafygreen-ui-15ajumo" weight="medium">
    Interaction with
    <code class="leafygreen-ui-1l06pbn">
     allowDiskUseByDefault
    </code>
    <a class="headerlink leafygreen-ui-1kepx47" href="#interaction-with-allowdiskusebydefault" title="Permalink to this heading">
     <svg aria-label="Link Icon" class="leafygreen-ui-a30zj9" fill="none" height="12" role="img" viewbox="0 0 16 16" width="12" xmlns="http://www.w3.org/2000/svg">
      <path d="M6.039 9.953a3.596 3.596 0 0 1-.327-.38l1.45-1.445a1.553 1.553 0 0 0 2.496.423l2.885-2.87a1.57 1.57 0 0 0 .01-2.213 1.553 1.553 0 0 0-2.203-.01l-.379.377A.995.995 0 0 1 8.56 3.83a1.005 1.005 0 0 1 .006-1.418l.38-.377a3.542 3.542 0 0 1 5.024.023 3.58 3.58 0 0 1-.022 5.047l-2.884 2.871a3.542 3.542 0 0 1-5.025-.022Z" fill="currentColor">
      </path>
      <path d="M9.961 6.047c.12.12.228.248.327.38l-1.45 1.445a1.553 1.553 0 0 0-2.496-.423l-2.885 2.87a1.57 1.57 0 0 0-.01 2.213 1.553 1.553 0 0 0 2.203.01l.379-.377a.995.995 0 0 1 1.411.006 1.005 1.005 0 0 1-.006 1.418l-.38.377a3.542 3.542 0 0 1-5.024-.023 3.58 3.58 0 0 1 .022-5.047l2.884-2.871a3.542 3.542 0 0 1 5.025.022Z" fill="currentColor">
      </path>
     </svg>
     <div class="css-1btu0w3 evvkmar0" id="interaction-with-allowdiskusebydefault">
     </div>
    </a>
   </h3>
   <p class="leafygreen-ui-1kp3ins">
    Starting in MongoDB 6.0, pipeline stages that require more than 100
megabytes of memory to execute write temporary files to disk by
default.
   </p>
   <div class="leafygreen-ui-15mdk4" role="note">
    <h2 class="leafygreen-ui-6n7b7d">
     Note
    </h2>
    <div class="leafygreen-ui-9mycqc">
     <p class="leafygreen-ui-1kp3ins">
      Prior to MongoDB 6.0,
      <code class="leafygreen-ui-1l06pbn">
       .allowDiskUse(false)
      </code>
      and
      <code class="leafygreen-ui-1l06pbn">
       .allowDiskUse(true)
      </code>
      have the same effect. In MongoDB 6.0, both
      <code class="leafygreen-ui-1l06pbn">
       mongosh
      </code>
      and the legacy
      <code class="leafygreen-ui-1l06pbn">
       mongo
      </code>
      shell behave the following way:
     </p>
    </div>
   </div>
   <p class="leafygreen-ui-1kp3ins">
    If
    <a class="leafygreen-ui-tqgtui" href="/docs/manual/reference/parameters/#mongodb-parameter-param.allowDiskUseByDefault">
     <code class="leafygreen-ui-1l06pbn">
      allowDiskUseByDefault
     </code>
    </a>
    is
    <code class="leafygreen-ui-1l06pbn">
     true
    </code>
    (this is the default):
   </p>
   <ul class="leafygreen-ui-rioki0">
    <li class="leafygreen-ui-d7p7b6">
     <p class="leafygreen-ui-1kp3ins">
      <code class="leafygreen-ui-1l06pbn">
       .allowDiskUse()
      </code>
      has no additional effect
     </p>
    </li>
    <li class="leafygreen-ui-d7p7b6">
     <p class="leafygreen-ui-1kp3ins">
      <code class="leafygreen-ui-1l06pbn">
       .allowDiskUse(true)
      </code>
      has no additional effect
     </p>
    </li>
    <li class="leafygreen-ui-d7p7b6">
     <p class="leafygreen-ui-1kp3ins">
      <code class="leafygreen-ui-1l06pbn">
       .allowDiskUse(false)
      </code>
      prohibits the query from writing temporary
files to disk
     </p>
    </li>
   </ul>
   <p class="leafygreen-ui-1kp3ins">
    If
    <a class="leafygreen-ui-tqgtui" href="/docs/manual/reference/parameters/#mongodb-parameter-param.allowDiskUseByDefault">
     <code class="leafygreen-ui-1l06pbn">
      allowDiskUseByDefault
     </code>
    </a>
    is
    <code class="leafygreen-ui-1l06pbn">
     false
    </code>
    :
   </p>
   <ul class="leafygreen-ui-rioki0">
    <li class="leafygreen-ui-d7p7b6">
     <p class="leafygreen-ui-1kp3ins">
      <code class="leafygreen-ui-1l06pbn">
       .allowDiskUse()
      </code>
      enables writing temporary files to disk
     </p>
    </li>
    <li class="leafygreen-ui-d7p7b6">
     <p class="leafygreen-ui-1kp3ins">
      <code class="leafygreen-ui-1l06pbn">
       .allowDiskUse(true)
      </code>
      enables writing temporary files to disk
     </p>
    </li>
    <li class="leafygreen-ui-d7p7b6">
     <p class="leafygreen-ui-1kp3ins">
      <code class="leafygreen-ui-1l06pbn">
       .allowDiskUse(false)
      </code>
      has no additional effect
     </p>
    </li>
   </ul>
  </section>
  <section>
   <h3 class="contains-headerlink leafygreen-ui-15ajumo" weight="medium">
    Supports Large Non-Indexed Sorts Only
    <a class="headerlink leafygreen-ui-1kepx47" href="#supports-large-non-indexed-sorts-only" title="Permalink to this heading">
     <svg aria-label="Link Icon" class="leafygreen-ui-a30zj9" fill="none" height="12" role="img" viewbox="0 0 16 16" width="12" xmlns="http://www.w3.org/2000/svg">
      <path d="M6.039 9.953a3.596 3.596 0 0 1-.327-.38l1.45-1.445a1.553 1.553 0 0 0 2.496.423l2.885-2.87a1.57 1.57 0 0 0 .01-2.213 1.553 1.553 0 0 0-2.203-.01l-.379.377A.995.995 0 0 1 8.56 3.83a1.005 1.005 0 0 1 .006-1.418l.38-.377a3.542 3.542 0 0 1 5.024.023 3.58 3.58 0 0 1-.022 5.047l-2.884 2.871a3.542 3.542 0 0 1-5.025-.022Z" fill="currentColor">
      </path>
      <path d="M9.961 6.047c.12.12.228.248.327.38l-1.45 1.445a1.553 1.553 0 0 0-2.496-.423l-2.885 2.87a1.57 1.57 0 0 0-.01 2.213 1.553 1.553 0 0 0 2.203.01l.379-.377a.995.995 0 0 1 1.411.006 1.005 1.005 0 0 1-.006 1.418l-.38.377a3.542 3.542 0 0 1-5.024-.023 3.58 3.58 0 0 1 .022-5.047l2.884-2.871a3.542 3.542 0 0 1 5.025.022Z" fill="currentColor">
      </path>
     </svg>
     <div class="css-1btu0w3 evvkmar0" id="supports-large-non-indexed-sorts-only">
     </div>
    </a>
   </h3>
   <p class="leafygreen-ui-1kp3ins">
    <a class="lg-ui-0001 leafygreen-ui-fgcsv5" href="#mongodb-method-cursor.allowDiskUse" target="_self">
     <span>
      <code class="leafygreen-ui-1l06pbn">
       cursor.allowDiskUse()
      </code>
     </span>
    </a>
    has no effect on sort operations
answered using an index
    <em>
     or
    </em>
    non-indexed ("blocking") sort operations
which require less than 100 megabytes of memory. For more complete
documentation on blocking sorts and sort index use, see
    <a class="leafygreen-ui-tqgtui" href="/docs/manual/reference/method/cursor.sort/#std-label-sort-index-use">
     Sort and Index Use
     <!-- -->
     .
    </a>
   </p>
   <p class="leafygreen-ui-1kp3ins">
    To check if MongoDB must perform an blocking sort, append
    <a class="leafygreen-ui-tqgtui" href="/docs/manual/reference/method/cursor.explain/#mongodb-method-cursor.explain">
     <code class="leafygreen-ui-1l06pbn">
      cursor.explain()
     </code>
    </a>
    to the query and check the
    <a class="leafygreen-ui-tqgtui" href="/docs/manual/reference/explain-results/#std-label-explain-results">
     explain results
    </a>
    . If the query plan
contains a
    <code class="leafygreen-ui-1l06pbn">
     SORT
    </code>
    stage, then MongoDB must perform an
blocking sort operation subject to the 100 megabyte memory limit.
   </p>
  </section>
 </section>
 <section>
  <h2 class="contains-headerlink leafygreen-ui-19f71ei" weight="medium">
   Example
   <a class="headerlink leafygreen-ui-1kepx47" href="#example" title="Permalink to this heading">
    <svg aria-label="Link Icon" class="leafygreen-ui-a30zj9" fill="none" height="12" role="img" viewbox="0 0 16 16" width="12" xmlns="http://www.w3.org/2000/svg">
     <path d="M6.039 9.953a3.596 3.596 0 0 1-.327-.38l1.45-1.445a1.553 1.553 0 0 0 2.496.423l2.885-2.87a1.57 1.57 0 0 0 .01-2.213 1.553 1.553 0 0 0-2.203-.01l-.379.377A.995.995 0 0 1 8.56 3.83a1.005 1.005 0 0 1 .006-1.418l.38-.377a3.542 3.542 0 0 1 5.024.023 3.58 3.58 0 0 1-.022 5.047l-2.884 2.871a3.542 3.542 0 0 1-5.025-.022Z" fill="currentColor">
     </path>
     <path d="M9.961 6.047c.12.12.228.248.327.38l-1.45 1.445a1.553 1.553 0 0 0-2.496-.423l-2.885 2.87a1.57 1.57 0 0 0-.01 2.213 1.553 1.553 0 0 0 2.203.01l.379-.377a.995.995 0 0 1 1.411.006 1.005 1.005 0 0 1-.006 1.418l-.38.377a3.542 3.542 0 0 1-5.024-.023 3.58 3.58 0 0 1 .022-5.047l2.884-2.871a3.542 3.542 0 0 1 5.025.022Z" fill="currentColor">
     </path>
    </svg>
    <div class="css-1btu0w3 evvkmar0" id="example">
    </div>
   </a>
  </h2>
  <p class="leafygreen-ui-1kp3ins">
   Consider a collection
   <code class="leafygreen-ui-1l06pbn">
    sensors
   </code>
   with only the default index on
   <code class="leafygreen-ui-1l06pbn">
    _id
   </code>
   . The collection contains documents similar to the
following:
  </p>
  <script class="structured_data" type="application/ld+json">
   {"@context":"https://schema.org","@type":"SoftwareSourceCode","codeSampleType":"code snippet","text":"{\n  \"sensor-name\" : \"TEMP-21425\",\n  \"sensor-location\" : \"Unit 12\",\n  \"reading\" : {\n    \"timestamp\" : Timestamp(1580247215, 1),\n    \"value\" : 212,\n    \"unit\" : \"Fahrenheit\"\n  }\n}","programmingLanguage":"JSON"}
  </script>
  <div class="css-1lju8ps">
   <div class="leafygreen-ui-196mwvg">
    <div class="leafygreen-ui-1jheeh3">
     <pre class="leafygreen-ui-1453az5" tabindex="-1"><code class="lg-highlight-hljs-light json leafygreen-ui-9ybzas"><table class="leafygreen-ui-1tr4g10"><tbody><tr class=""><td class="leafygreen-ui-7razhx"><span class="lg-highlight-punctuation">{</span></td></tr><tr class=""><td class="leafygreen-ui-7razhx">  <span class="lg-highlight-attr">"sensor-name"</span> <span class="lg-highlight-punctuation">:</span> <span class="lg-highlight-string">"TEMP-21425"</span><span class="lg-highlight-punctuation">,</span></td></tr><tr class=""><td class="leafygreen-ui-7razhx">  <span class="lg-highlight-attr">"sensor-location"</span> <span class="lg-highlight-punctuation">:</span> <span class="lg-highlight-string">"Unit 12"</span><span class="lg-highlight-punctuation">,</span></td></tr><tr class=""><td class="leafygreen-ui-7razhx">  <span class="lg-highlight-attr">"reading"</span> <span class="lg-highlight-punctuation">:</span> <span class="lg-highlight-punctuation">{</span></td></tr><tr class=""><td class="leafygreen-ui-7razhx">    <span class="lg-highlight-attr">"timestamp"</span> <span class="lg-highlight-punctuation">:</span> Timestamp(<span class="lg-highlight-number">1580247215</span><span class="lg-highlight-punctuation">,</span> <span class="lg-highlight-number">1</span>)<span class="lg-highlight-punctuation">,</span></td></tr><tr class=""><td class="leafygreen-ui-7razhx">    <span class="lg-highlight-attr">"value"</span> <span class="lg-highlight-punctuation">:</span> <span class="lg-highlight-number">212</span><span class="lg-highlight-punctuation">,</span></td></tr><tr class=""><td class="leafygreen-ui-7razhx">    <span class="lg-highlight-attr">"unit"</span> <span class="lg-highlight-punctuation">:</span> <span class="lg-highlight-string">"Fahrenheit"</span></td></tr><tr class=""><td class="leafygreen-ui-7razhx">  <span class="lg-highlight-punctuation">}</span></td></tr><tr class=""><td class="leafygreen-ui-7razhx"><span class="lg-highlight-punctuation">}</span></td></tr></tbody></table></code></pre>
    </div>
   </div>
  </div>
  <p class="leafygreen-ui-1kp3ins">
   The following operation includes a
   <a class="leafygreen-ui-tqgtui" href="/docs/manual/reference/method/cursor.sort/#mongodb-method-cursor.sort">
    <code class="leafygreen-ui-1l06pbn">
     cursor.sort()
    </code>
   </a>
   on the
field
   <code class="leafygreen-ui-1l06pbn">
    reading.timestamp
   </code>
   . The operation also includes
   <a class="lg-ui-0001 leafygreen-ui-fgcsv5" href="#mongodb-method-cursor.allowDiskUse" target="_self">
    <span>
     <code class="leafygreen-ui-1l06pbn">
      cursor.allowDiskUse()
     </code>
    </span>
   </a>
   to support the sort operation.
  </p>
  <script class="structured_data" type="application/ld+json">
   {"@context":"https://schema.org","@type":"SoftwareSourceCode","codeSampleType":"code snippet","text":"db.sensors.find({\"sensor-location\" : \"Unit 12\"}).\n  sort({\"reading.timestamp\" : 1}).\n  allowDiskUse()","programmingLanguage":"JavaScript"}
  </script>
  <div class="css-16lmvu9">
   <div class="leafygreen-ui-196mwvg">
    <div class="leafygreen-ui-yzcs8i">
     <pre class="leafygreen-ui-11itue3" tabindex="-1"><code class="lg-highlight-hljs-light javascript leafygreen-ui-9ybzas"><table class="leafygreen-ui-1tr4g10"><tbody><tr class=""><td class="leafygreen-ui-7razhx">db.<span class="lg-highlight-property">sensors</span>.<span class="lg-highlight-title lg-highlight-function">find</span>(<!-- -->{<span class="lg-highlight-string">"sensor-location"</span> <!-- -->: <span class="lg-highlight-string">"Unit 12"</span>}).</td></tr><tr class=""><td class="leafygreen-ui-7razhx">  <span class="lg-highlight-title lg-highlight-function">sort</span>(<!-- -->{<span class="lg-highlight-string">"reading.timestamp"</span> <!-- -->: <span class="lg-highlight-number">1</span>}).</td></tr><tr class=""><td class="leafygreen-ui-7razhx">  <span class="lg-highlight-title lg-highlight-function">allowDiskUse</span>(<!-- -->)</td></tr></tbody></table></code></pre>
     <div class="leafygreen-ui-1bqcprk" data-testid="leafygreen-code-panel">
      <button aria-disabled="false" aria-label="Copy" class="leafygreen-ui-1c6zwke" data-testid="code_copy-button" tabindex="0">
       <div class="leafygreen-ui-xhlipt">
        <svg aria-label="Copy Icon" class="leafygreen-ui-1st74h4" height="16" role="img" viewbox="0 0 16 16" width="16">
         <path clip-rule="evenodd" d="M1 5.71428V10.2857C1 11.2325 1.76751 12 2.71429 12H5.75V7.10957C5.75 6.54414 5.97724 6.00244 6.38065 5.60623L8.67403 3.35381C8.77447 3.25516 8.88376 3.16757 9 3.09182V2.71429C9 1.76751 8.23249 1 7.28571 1H5.8V4.42857C5.8 5.13865 5.22437 5.71428 4.51429 5.71428H1ZM9 4.78571L7.25654 6.49804C7.24689 6.50752 7.23749 6.5172 7.22834 6.52708C7.22208 6.53383 7.21594 6.54068 7.20991 6.54762C7.07504 6.70295 7 6.90234 7 7.10957V7.79762H9H10.0095C10.4829 7.79762 10.8667 7.41386 10.8667 6.94047V4H10.1505C9.92587 4 9.7102 4.0882 9.54992 4.24562L9 4.78571ZM4.86667 1H4.15053C3.92587 1 3.7102 1.0882 3.54992 1.24562L1.25654 3.49804C1.09244 3.65921 1 3.87957 1 4.10957V4.79762H4.00952C4.48291 4.79762 4.86667 4.41386 4.86667 3.94047V1ZM7 12V8.71428H9H10.5143C11.2244 8.71428 11.8 8.13865 11.8 7.42857V4H13.2857C14.2325 4 15 4.76751 15 5.71429V13.2857C15 14.2325 14.2325 15 13.2857 15H8.71429C7.76751 15 7 14.2325 7 13.2857V12Z" fill="currentColor" fill-rule="evenodd">
         </path>
        </svg>
       </div>
      </button>
     </div>
    </div>
   </div>
  </div>
  <p class="leafygreen-ui-1kp3ins">
   Since
   <code class="leafygreen-ui-1l06pbn">
    reading.timestamp
   </code>
   is not included in an index, MongoDB
must perform a blocking sort operation to return results in the
requested sort order. By specifying
   <a class="lg-ui-0001 leafygreen-ui-fgcsv5" href="#mongodb-method-cursor.allowDiskUse" target="_self">
    <span>
     <code class="leafygreen-ui-1l06pbn">
      allowDiskUse()
     </code>
    </span>
   </a>
   ,
MongoDB can process the sort operation
   <em>
    even if
   </em>
   it requires more than
100 megabytes of system memory. If
   <a class="lg-ui-0001 leafygreen-ui-fgcsv5" href="#mongodb-method-cursor.allowDiskUse" target="_self">
    <span>
     <code class="leafygreen-ui-1l06pbn">
      allowDiskUse()
     </code>
    </span>
   </a>
   was omitted
   <em>
    and
   </em>
   the operation required more than 100 megabytes of
system memory, MongoDB would return an error.
  </p>
 </section>
</section>
