> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kinetica.com/llms.txt
> Use this file to discover all available pages before exploring further.

# alterWal

<div className="kinetica-doxygen">
  <div id="a982dab90baf6bd12035b69342f8187a3" />

  <h2 className="memtitle"><span className="permalink"><a href="#a982dab90baf6bd12035b69342f8187a3">◆ </a></span>alterWal() <span className="overload">\[1/4]</span></h2>

  <div className="memitem">
    <div className="memproto">
      <table className="memname">
        <tr>
          <td className="memname"><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">AlterWalResponse</a> gpudb::GPUdb::alterWal </td>
          <td>(</td>
          <td className="paramtype">const <a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalRequest">AlterWalRequest</a> &</td>
          <td className="paramname"><span className="paramname"><span className="em">request\_</span></span></td>
          <td>)</td>
          <td> const</td>
        </tr>
      </table>
    </div>

    <div className="memdoc">
      <p>Alters table write-ahead log (WAL) settings. </p>
      <p>Returns information about the requested table WAL modifications.</p>

      <div className="dl params">
        <div className="dt">Parameters</div>

        <div className="dd">
          <table className="params">
            <tr>
              <td className="paramdir">\[in]</td>
              <td className="paramname">request\_</td>
              <td><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalRequest">Request</a> object containing the parameters for the operation.</td>
            </tr>
          </table>
        </div>
      </div>

      <div className="dl section return">
        <div className="dt">Returns</div>
        <div className="dd"><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">Response</a> object containing the result of the operation. </div>
      </div>
    </div>
  </div>

  <div id="af3d0a716ce6da913df55c114c99d7cb1" />

  <h2 className="memtitle"><span className="permalink"><a href="#af3d0a716ce6da913df55c114c99d7cb1">◆ </a></span>alterWal() <span className="overload">\[2/4]</span></h2>

  <div className="memitem">
    <div className="memproto">
      <table className="memname">
        <tr>
          <td className="memname"><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">AlterWalResponse</a> & gpudb::GPUdb::alterWal </td>
          <td>(</td>
          <td className="paramtype">const <a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalRequest">AlterWalRequest</a> &</td>
          <td className="paramname"><span className="paramname"><span className="em">request\_</span></span>, </td>
        </tr>

        <tr>
          <td className="paramkey" />

          <td />

          <td className="paramtype"><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">AlterWalResponse</a> &</td>
          <td className="paramname"><span className="paramname"><span className="em">response\_</span></span> ) const</td>
        </tr>
      </table>
    </div>

    <div className="memdoc">
      <p>Alters table write-ahead log (WAL) settings. </p>
      <p>Returns information about the requested table WAL modifications.</p>

      <div className="dl params">
        <div className="dt">Parameters</div>

        <div className="dd">
          <table className="params">
            <tr>
              <td className="paramdir">\[in]</td>
              <td className="paramname">request\_</td>
              <td><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalRequest">Request</a> object containing the parameters for the operation. </td>
            </tr>

            <tr>
              <td className="paramdir">\[out]</td>
              <td className="paramname">response\_</td>
              <td><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">Response</a> object containing the results of the operation.</td>
            </tr>
          </table>
        </div>
      </div>

      <div className="dl section return">
        <div className="dt">Returns</div>
        <div className="dd"><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">Response</a> object containing the result of the operation (initially passed in by reference). </div>
      </div>
    </div>
  </div>

  <div id="ae392fc22d368ad7a63525ad09fb333b8" />

  <h2 className="memtitle"><span className="permalink"><a href="#ae392fc22d368ad7a63525ad09fb333b8">◆ </a></span>alterWal() <span className="overload">\[3/4]</span></h2>

  <div className="memitem">
    <div className="memproto">
      <table className="memname">
        <tr>
          <td className="memname"><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">AlterWalResponse</a> gpudb::GPUdb::alterWal </td>
          <td>(</td>
          <td className="paramtype">const std::vector\< std::string > &</td>
          <td className="paramname"><span className="paramname"><span className="em">tableNames</span></span>, </td>
        </tr>

        <tr>
          <td className="paramkey" />

          <td />

          <td className="paramtype">const std::map\< std::string, std::string > &</td>
          <td className="paramname"><span className="paramname"><span className="em">options</span></span> ) const</td>
        </tr>
      </table>
    </div>

    <div className="memdoc">
      <p>Alters table write-ahead log (WAL) settings. </p>
      <p>Returns information about the requested table WAL modifications.</p>

      <div className="dl params">
        <div className="dt">Parameters</div>

        <div className="dd">
          <table className="params">
            <tr>
              <td className="paramdir">\[in]</td>
              <td className="paramname">tableNames</td>
              <td>List of tables to modify. An asterisk changes the system settings. </td>
            </tr>

            <tr>
              <td className="paramdir">\[in]</td>
              <td className="paramname">options</td>

              <td>
                Optional parameters.

                <ul>
                  <li> <a className="el" href="/content/api/cpp/namespacegpudb#a11243780573269b0188f43086fefd487">alter\_wal\_max\_segment\_size</a>: Maximum size of an individual segment file. </li>
                  <li> <a className="el" href="/content/api/cpp/namespacegpudb#a2cc00dc1d5af908a8cb471d1672a047b">alter\_wal\_segment\_count</a>: Approximate number of segment files to split the WAL across. Must be at least two. </li>

                  <li>
                    <a className="el" href="/content/api/cpp/namespacegpudb#ae521bb194a9ce38e75609142cd93becf">alter\_wal\_sync\_policy</a>: Maximum size of an individual segment file. Supported values:

                    <ul>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#a91d162ed444e2e9085c605c28c877e00">alter\_wal\_none</a>: Disables the WAL. </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#ad2fe01c6f5978e3e7236facab116f4a2">alter\_wal\_background</a>: WAL entries are periodically written instead of immediately after each operation. </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#ae10a93be3787862b80aab1897fb52e33">alter\_wal\_flush</a>: Protects entries in the event of a database crash. </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#aae23b82ae4ff72a7ea1a7086fa15a02b">alter\_wal\_fsync</a>: Protects entries in the event of an OS crash. </li>
                    </ul>
                  </li>

                  <li> <a className="el" href="/content/api/cpp/namespacegpudb#ac171e13c8202fc9465715d3b417db8f0">alter\_wal\_flush\_frequency</a>: Specifies how frequently WAL entries are written with background sync. This is a global setting and can only be used with the system {"{"}options.table\_names{"}"} specifier '\*'. </li>

                  <li>
                    <a className="el" href="/content/api/cpp/namespacegpudb#afda614e8703a8cbfcbd7341c53356a80">alter\_wal\_checksum</a>: If <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">true</a> each entry will be checked against a protective checksum. Supported values:

                    <ul>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a> </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a> </li>
                    </ul>

                    The default value is <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a>.
                  </li>

                  <li>
                    <a className="el" href="/content/api/cpp/namespacegpudb#a3bf4a86f684e5f72efca3f49eb6606c7">alter\_wal\_override\_non\_default</a>: If <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">true</a> tables with unique WAL settings will be overridden when applying a system level change. Supported values:

                    <ul>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a> </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a> </li>
                    </ul>

                    The default value is <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a>.
                  </li>

                  <li>
                    <a className="el" href="/content/api/cpp/namespacegpudb#ae1945c992a9ac4f5a9e6d7182ad084f5">alter\_wal\_restore\_system\_settings</a>: If <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">true</a> tables with unique WAL settings will be reverted to the current global settings. Cannot be used in conjunction with any other option. Supported values:

                    <ul>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a> </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a> </li>
                    </ul>

                    The default value is <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a>.
                  </li>

                  <li>
                    <a className="el" href="/content/api/cpp/namespacegpudb#af6747739be3b5833037159b5e848e54e">alter\_wal\_persist</a>: If <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">true</a> and a system-level change was requested, the system configuration will be written to disk upon successful application of this request. This will commit the changes from this request and any additional in-memory modifications. Supported values:

                    <ul>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a> </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a> </li>
                    </ul>

                    The default value is <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a>.
                  </li>
                </ul>

                The default value is an empty map.
              </td>
            </tr>
          </table>
        </div>
      </div>

      <div className="dl section return">
        <div className="dt">Returns</div>
        <div className="dd"><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">Response</a> object containing the result of the operation. </div>
      </div>
    </div>
  </div>

  <div id="a87d7bf3ba965adcab6f283754f470c94" />

  <h2 className="memtitle"><span className="permalink"><a href="#a87d7bf3ba965adcab6f283754f470c94">◆ </a></span>alterWal() <span className="overload">\[4/4]</span></h2>

  <div className="memitem">
    <div className="memproto">
      <table className="memname">
        <tr>
          <td className="memname"><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">AlterWalResponse</a> & gpudb::GPUdb::alterWal </td>
          <td>(</td>
          <td className="paramtype">const std::vector\< std::string > &</td>
          <td className="paramname"><span className="paramname"><span className="em">tableNames</span></span>, </td>
        </tr>

        <tr>
          <td className="paramkey" />

          <td />

          <td className="paramtype">const std::map\< std::string, std::string > &</td>
          <td className="paramname"><span className="paramname"><span className="em">options</span></span>, </td>
        </tr>

        <tr>
          <td className="paramkey" />

          <td />

          <td className="paramtype"><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">AlterWalResponse</a> &</td>
          <td className="paramname"><span className="paramname"><span className="em">response\_</span></span> ) const</td>
        </tr>
      </table>
    </div>

    <div className="memdoc">
      <p>Alters table write-ahead log (WAL) settings. </p>
      <p>Returns information about the requested table WAL modifications.</p>

      <div className="dl params">
        <div className="dt">Parameters</div>

        <div className="dd">
          <table className="params">
            <tr>
              <td className="paramdir">\[in]</td>
              <td className="paramname">tableNames</td>
              <td>List of tables to modify. An asterisk changes the system settings. </td>
            </tr>

            <tr>
              <td className="paramdir">\[in]</td>
              <td className="paramname">options</td>

              <td>
                Optional parameters.

                <ul>
                  <li> <a className="el" href="/content/api/cpp/namespacegpudb#a11243780573269b0188f43086fefd487">alter\_wal\_max\_segment\_size</a>: Maximum size of an individual segment file. </li>
                  <li> <a className="el" href="/content/api/cpp/namespacegpudb#a2cc00dc1d5af908a8cb471d1672a047b">alter\_wal\_segment\_count</a>: Approximate number of segment files to split the WAL across. Must be at least two. </li>

                  <li>
                    <a className="el" href="/content/api/cpp/namespacegpudb#ae521bb194a9ce38e75609142cd93becf">alter\_wal\_sync\_policy</a>: Maximum size of an individual segment file. Supported values:

                    <ul>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#a91d162ed444e2e9085c605c28c877e00">alter\_wal\_none</a>: Disables the WAL. </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#ad2fe01c6f5978e3e7236facab116f4a2">alter\_wal\_background</a>: WAL entries are periodically written instead of immediately after each operation. </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#ae10a93be3787862b80aab1897fb52e33">alter\_wal\_flush</a>: Protects entries in the event of a database crash. </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#aae23b82ae4ff72a7ea1a7086fa15a02b">alter\_wal\_fsync</a>: Protects entries in the event of an OS crash. </li>
                    </ul>
                  </li>

                  <li> <a className="el" href="/content/api/cpp/namespacegpudb#ac171e13c8202fc9465715d3b417db8f0">alter\_wal\_flush\_frequency</a>: Specifies how frequently WAL entries are written with background sync. This is a global setting and can only be used with the system {"{"}options.table\_names{"}"} specifier '\*'. </li>

                  <li>
                    <a className="el" href="/content/api/cpp/namespacegpudb#afda614e8703a8cbfcbd7341c53356a80">alter\_wal\_checksum</a>: If <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">true</a> each entry will be checked against a protective checksum. Supported values:

                    <ul>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a> </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a> </li>
                    </ul>

                    The default value is <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a>.
                  </li>

                  <li>
                    <a className="el" href="/content/api/cpp/namespacegpudb#a3bf4a86f684e5f72efca3f49eb6606c7">alter\_wal\_override\_non\_default</a>: If <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">true</a> tables with unique WAL settings will be overridden when applying a system level change. Supported values:

                    <ul>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a> </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a> </li>
                    </ul>

                    The default value is <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a>.
                  </li>

                  <li>
                    <a className="el" href="/content/api/cpp/namespacegpudb#ae1945c992a9ac4f5a9e6d7182ad084f5">alter\_wal\_restore\_system\_settings</a>: If <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">true</a> tables with unique WAL settings will be reverted to the current global settings. Cannot be used in conjunction with any other option. Supported values:

                    <ul>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a> </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a> </li>
                    </ul>

                    The default value is <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a>.
                  </li>

                  <li>
                    <a className="el" href="/content/api/cpp/namespacegpudb#af6747739be3b5833037159b5e848e54e">alter\_wal\_persist</a>: If <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">true</a> and a system-level change was requested, the system configuration will be written to disk upon successful application of this request. This will commit the changes from this request and any additional in-memory modifications. Supported values:

                    <ul>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a> </li>
                      <li> <a className="el" href="/content/api/cpp/namespacegpudb#afd2618a1b1b25668ee515a4f44133c9f">alter\_wal\_false</a> </li>
                    </ul>

                    The default value is <a className="el" href="/content/api/cpp/namespacegpudb#a05b6ab935abe46b7ad7f3d3be3bee137">alter\_wal\_true</a>.
                  </li>
                </ul>

                The default value is an empty map.
              </td>
            </tr>

            <tr>
              <td className="paramdir">\[out]</td>
              <td className="paramname">response\_</td>
              <td><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">Response</a> object containing the results of the operation.</td>
            </tr>
          </table>
        </div>
      </div>

      <div className="dl section return">
        <div className="dt">Returns</div>
        <div className="dd"><a className="el" href="/content/api/cpp/structgpudb_1_1AlterWalResponse">Response</a> object containing the result of the operation (initially passed in by reference). </div>
      </div>
    </div>
  </div>
</div>