<section>
 <h1 class="contains-headerlink leafygreen-ui-41fr9s" weight="medium">
  Shard a Collection
  <a class="headerlink leafygreen-ui-1kepx47" href="#shard-a-collection" 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="shard-a-collection">
   </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="#shard-key-fields-and-values" target="_self">
     <span>
      Shard Key Fields and Values
     </span>
    </a>
   </li>
   <li class="leafygreen-ui-1jqtqlb">
    <a class="lg-ui-0001 leafygreen-ui-x9koo9" href="#missing-shard-key-fields" target="_self">
     <span>
      Missing Shard Key Fields
     </span>
    </a>
   </li>
   <li class="leafygreen-ui-1jqtqlb">
    <a class="lg-ui-0001 leafygreen-ui-x9koo9" href="#change-a-document-s-shard-key-value" target="_self">
     <span>
      Change a Document's Shard Key Value
     </span>
    </a>
   </li>
   <li class="leafygreen-ui-1jqtqlb">
    <a class="lg-ui-0001 leafygreen-ui-x9koo9" href="#change-a-collection-s-shard-key" target="_self">
     <span>
      Change a Collection's Shard Key
     </span>
    </a>
   </li>
  </ul>
 </div>
 <p class="leafygreen-ui-1kp3ins">
  To shard a collection, you must specify the full namespace of the
collection that you want to shard and the shard key. You can use the
  <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
  <a class="leafygreen-ui-tqgtui" href="/docs/manual/reference/method/sh.shardCollection/#mongodb-method-sh.shardCollection">
   <code class="leafygreen-ui-1l06pbn">
    sh.shardCollection()
   </code>
  </a>
  to
shard a collection:
 </p>
 <script class="structured_data" type="application/ld+json">
  {"@context":"https://schema.org","@type":"SoftwareSourceCode","codeSampleType":"code snippet","text":"sh.shardCollection(&lt;namespace&gt;, &lt;key&gt;) // Optional parameters omitted","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">sh.<span class="lg-highlight-title lg-highlight-function">shardCollection</span>(&lt;<!-- -->namespace<!-- -->&gt;<!-- -->,<!-- --> <!-- -->&lt;<!-- -->key<!-- -->&gt;<!-- -->) <span class="lg-highlight-comment">// Optional parameters omitted</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>
 <div class="leafygreen-ui-skkc39" tabindex="0">
  <table class="leafygreen-ui-hr8lsv">
   <colgroup>
    <col style="width:20%"/>
    <col style="width:80%"/>
   </colgroup>
   <thead class="leafygreen-ui-a9ho40">
   </thead>
   <tbody>
    <tr class="">
     <td class="leafygreen-ui-1drjk7h">
      <div class="leafygreen-ui-1n4j8xf">
       <div>
        <code class="leafygreen-ui-1l06pbn">
         namespace
        </code>
       </div>
      </div>
     </td>
     <td class="leafygreen-ui-1drjk7h">
      <div class="leafygreen-ui-1n4j8xf">
       <div>
        Specify the full namespace of the collection that you want to
shard (
        <code class="leafygreen-ui-1l06pbn">
         "&lt;database&gt;.&lt;collection&gt;"
        </code>
        ).
       </div>
      </div>
     </td>
    </tr>
    <tr class="">
     <td class="leafygreen-ui-1drjk7h">
      <div class="leafygreen-ui-1n4j8xf">
       <div>
        <code class="leafygreen-ui-1l06pbn">
         key
        </code>
       </div>
      </div>
     </td>
     <td class="leafygreen-ui-1drjk7h">
      <div class="leafygreen-ui-1n4j8xf">
       <div>
        <p class="leafygreen-ui-1kp3ins">
         Specify a document
         <code class="leafygreen-ui-1l06pbn">
          { &lt;shard key field1&gt;: &lt;1|"hashed"&gt;, ... }
         </code>
         where
        </p>
        <ul class="leafygreen-ui-rioki0">
         <li class="leafygreen-ui-d7p7b6">
          <p class="leafygreen-ui-1kp3ins">
           <code class="leafygreen-ui-1l06pbn">
            1
           </code>
           indicates
           <a class="leafygreen-ui-tqgtui" href="/docs/manual/core/ranged-sharding/#std-label-sharding-ranged">
            range-based sharding
           </a>
          </p>
         </li>
         <li class="leafygreen-ui-d7p7b6">
          <p class="leafygreen-ui-1kp3ins">
           <code class="leafygreen-ui-1l06pbn">
            "hashed"
           </code>
           indicates
           <a class="leafygreen-ui-tqgtui" href="/docs/manual/core/hashed-sharding/#std-label-sharding-hashed">
            hashed sharding
            <!-- -->
            .
           </a>
          </p>
         </li>
        </ul>
       </div>
      </div>
     </td>
    </tr>
   </tbody>
  </table>
 </div>
 <p class="leafygreen-ui-1kp3ins">
  For more information on the sharding method, see
  <a class="leafygreen-ui-tqgtui" href="/docs/manual/reference/method/sh.shardCollection/#mongodb-method-sh.shardCollection">
   <code class="leafygreen-ui-1l06pbn">
    sh.shardCollection()
   </code>
   .
  </a>
 </p>
 <section>
  <h2 class="contains-headerlink leafygreen-ui-19f71ei" weight="medium">
   Shard Key Fields and Values
   <a class="headerlink leafygreen-ui-1kepx47" href="#shard-key-fields-and-values" 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="shard-key-fields-and-values">
    </div>
   </a>
  </h2>
  <section>
   <h3 class="contains-headerlink leafygreen-ui-15ajumo" weight="medium">
    Missing Shard Key Fields
    <a class="headerlink leafygreen-ui-1kepx47" href="#missing-shard-key-fields" 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="missing-shard-key-fields">
     </div>
    </a>
   </h3>
   <p class="leafygreen-ui-1kp3ins">
    Documents in sharded collections can be missing the shard key fields.
A missing shard key falls into the same range as a
    <code class="leafygreen-ui-1l06pbn">
     null
    </code>
    -valued shard key.
See
    <a class="leafygreen-ui-tqgtui" href="/docs/manual/core/sharding-shard-key/#std-label-shard-key-missing">
     Missing Shard Key Fields
     <!-- -->
     .
    </a>
   </p>
  </section>
  <section>
   <h3 class="contains-headerlink leafygreen-ui-15ajumo" weight="medium">
    Change a Document's Shard Key Value
    <a class="headerlink leafygreen-ui-1kepx47" href="#change-a-document-s-shard-key-value" 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="change-a-document-s-shard-key-value">
     </div>
    </a>
   </h3>
   <p class="leafygreen-ui-1kp3ins">
    You can update a document's shard key value unless the shard key field is the
immutable
    <code class="leafygreen-ui-1l06pbn">
     _id
    </code>
    field.
   </p>
   <p class="leafygreen-ui-1kp3ins">
    For details on updating the shard key value, see
    <a class="leafygreen-ui-tqgtui" href="/docs/manual/core/sharding-change-shard-key-value/#std-label-update-shard-key">
     Change a Document's Shard Key Value
     <!-- -->
     .
    </a>
   </p>
  </section>
  <section>
   <h3 class="contains-headerlink leafygreen-ui-15ajumo" weight="medium">
    Change a Collection's Shard Key
    <a class="headerlink leafygreen-ui-1kepx47" href="#change-a-collection-s-shard-key" 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="change-a-collection-s-shard-key">
     </div>
    </a>
   </h3>
   <p class="leafygreen-ui-1kp3ins">
    Starting in MongoDB 5.0, you can
    <a class="leafygreen-ui-tqgtui" href="/docs/manual/core/sharding-reshard-a-collection/#std-label-sharding-resharding">
     reshard a collection
    </a>
    by changing a document's shard key.
   </p>
   <p class="leafygreen-ui-1kp3ins">
    You can
    <a class="leafygreen-ui-tqgtui" href="/docs/manual/core/sharding-refine-a-shard-key/#std-label-shard-key-refine">
     refine a shard key
    </a>
    by adding a suffix field
or fields to the existing shard key.
   </p>
  </section>
 </section>
</section>
