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    <div class="moz-cite-prefix">Hello,</div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">If the proposers want their files to be
      accessible by other applications, the best they could do is to use
      some of the mechanisms provided by HDF5 to use other formats like
      external storage and/or Virtual File Drivers and Virtual File
      Layer.<br>
    </div>
    <p><br>
    </p>
    <p><a class="moz-txt-link-freetext" href="https://confluence.hdfgroup.org/display/HDF5/Virtual+File+Layer">https://confluence.hdfgroup.org/display/HDF5/Virtual+File+Layer</a><br>
    </p>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">If they only care about their
      applications, they do not need to ask anything :-)<br>
    </div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">Cheers,</div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">Armando<br>
    </div>
    <div class="moz-cite-prefix"><br>
    </div>
    <div class="moz-cite-prefix">On 07/04/2022 19:16, Watts Benjamin
      (PSI) via NeXus wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:480d239c798442afbf0e1ee78140b10f@psi.ch">
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        <p>Hi Tobias,</p>
        <p>   I agree that we have spent the past decade recommending
          HDF5, but at the same time we have been saying that NeXus is
          about the organisation of data within the container, not the
          container file format itself. I can see that you feel
          surprised by the sudden discussion of other file formats, just
          as I was surprised to hear the community talking about it at
          the recent NFDI workshop. I am only advocating for discussion
          and I would like to hear your input.
          <span>I agree that multiple backends will introduce higher
            support requirements that NeXus doesn't currently have
            resources for.</span> Your preference for NeXus referring to
          a (small) defined set of file formats is a valid view point
          and I agree that there are practicalities to consider. I view
          the next telco as just the restart of an old discussion and
          nothing can really change until a proposal is brought to a
          NIAC meeting (and accepted).</p>
        <p><br>
        </p>
        <p>Cheers,</p>
        <p>Ben<br>
        </p>
      </div>
      <hr style="display:inline-block;width:98%" tabindex="-1">
      <div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt"
          face="Calibri, sans-serif" color="#000000"><b>From:</b> Tobias
          Richter <a class="moz-txt-link-rfc2396E" href="mailto:Tobias.Richter@ess.eu"><Tobias.Richter@ess.eu></a><br>
          <b>Sent:</b> Thursday, 7 April 2022 6:23:43 PM<br>
          <b>To:</b> Discussion forum for the NeXus data format;
          <a class="moz-txt-link-abbreviated" href="mailto:nexus@nexusformat.org">nexus@nexusformat.org</a><br>
          <b>Cc:</b> Watts Benjamin (PSI); Alexander Debus; Nicolas
          Soler; Franz Pöschel; Emilio Centeno Ortiz<br>
          <b>Subject:</b> Re: [Nexus] HDF5 as NeXus file format</font>
        <div> </div>
      </div>
      <div>
        <div class="WordSection1">
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US">Hi
              all,<o:p></o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US">According
              to this discussion from a decade ago HDF5 is singled out
              as the only preferred physical file format:
              <a href="https://www.nexusformat.org/NIAC2012"
                moz-do-not-send="true" class="moz-txt-link-freetext">https://www.nexusformat.org/NIAC2012</a><o:p></o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
          <ul type="disc">
            <li class="MsoNormal"
style="color:#515151;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0
              level1 lfo1;background:white">
              <span style="font-size:13.5pt;font-family:"PT
                Sans",sans-serif">NeXus guiding statements:<o:p></o:p></span>
              <ul type="circle">
                <li class="MsoNormal"
style="color:#515151;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0
                  level2 lfo1;background:white">
                  <span style="font-size:13.5pt;font-family:"PT
                    Sans",sans-serif">The main focus of the NeXus
                    community is to further develop the dictionaries,
                    base classes and application definitions.<o:p></o:p></span></li>
                <li class="MsoNormal"
style="color:#515151;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0
                  level2 lfo1;background:white">
                  <span style="font-size:13.5pt;font-family:"PT
                    Sans",sans-serif">The NIAC is a forum for
                    resolving issues.<o:p></o:p></span></li>
                <li class="MsoNormal"
style="color:#515151;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0
                  level2 lfo1;background:white">
                  <span style="font-size:13.5pt;font-family:"PT
                    Sans",sans-serif">The NIAC acts as a custodian
                    for NeXus: definitions, examples, documentation,
                    reference implementations.<o:p></o:p></span></li>
                <li class="MsoNormal"
style="color:#515151;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0
                  level2 lfo1;background:white">
                  <span style="font-size:13.5pt;font-family:"PT
                    Sans",sans-serif">NeXus can be mapped to
                    different physical file formats:<o:p></o:p></span>
                  <ul type="square">
                    <li class="MsoNormal"
style="color:#515151;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0
                      level3 lfo1;background:white">
                      <span style="font-size:13.5pt;font-family:"PT
                        Sans",sans-serif">HDF5 is the preferred
                        physical file format.<o:p></o:p></span></li>
                    <li class="MsoNormal"
style="color:#515151;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0
                      level3 lfo1;background:white">
                      <span style="font-size:13.5pt;font-family:"PT
                        Sans",sans-serif">NeXus-XML is the
                        currently supported ASCII file format.<o:p></o:p></span></li>
                  </ul>
                </li>
              </ul>
            </li>
          </ul>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US">Technically
              you can map into different backends. Yes. XML is still
              sort of supported. At the time it was requested that other
              options would get the official blessing (YAML being
              specifically asked for) but for practical exchange between
              facilities the consensus was to stick with HDF5.
              <o:p></o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US">There
              no longer is a recommended or fully maintained abstraction
              layer (like NAPI) to do an on the fly translation between
              backends. Who would be in charge of defining how the
              “official” mapping into sqlite or whatever would look
              like? How many backends can the community commit to
              support in the long run?<o:p></o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US">When
              tools that are currently developed/supported/maintained to
              “read” NeXus/HDF5 fail to work with what gets handed out,
              we are in a worse situation than we are now. Note: What
              facilities do internally for performance optimisations or
              other reasons could be different, if it stays internal.
              But I am clearly a lot less open minded about producing
              non-HDF5 files with a “NeXus” label than Ben. Maybe I
              missed some decisions that were taken lately in this
              direction or we’re no longer interested in being able to
              read each other’s files. Should either be the case, I’ll
              be quiet.<o:p></o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US">Best
              wishes,<o:p></o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US">Tobias<o:p></o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
          <p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
          <div style="border:none;border-top:solid #B5C4DF
            1.0pt;padding:3.0pt 0cm 0cm 0cm">
            <p class="MsoNormal" style="margin-left:36.0pt"><b><span
                  style="font-size:12.0pt;color:black">From:
                </span></b><span style="font-size:12.0pt;color:black">NeXus
                <a class="moz-txt-link-rfc2396E" href="mailto:nexus-bounces@shadow.nd.rl.ac.uk"><nexus-bounces@shadow.nd.rl.ac.uk></a> on behalf of
                "Watts Benjamin (PSI) via NeXus"
                <a class="moz-txt-link-rfc2396E" href="mailto:nexus@shadow.nd.rl.ac.uk"><nexus@shadow.nd.rl.ac.uk></a><br>
                <b>Reply to: </b>Discussion forum for the NeXus data
                format <a class="moz-txt-link-rfc2396E" href="mailto:nexus@shadow.nd.rl.ac.uk"><nexus@shadow.nd.rl.ac.uk></a><br>
                <b>Date: </b>Thursday, 7 April 2022 at 17:10<br>
                <b>To: </b><a class="moz-txt-link-rfc2396E" href="mailto:nexus@nexusformat.org">"nexus@nexusformat.org"</a>
                <a class="moz-txt-link-rfc2396E" href="mailto:nexus@nexusformat.org"><nexus@nexusformat.org></a><br>
                <b>Cc: </b>Benjamin Watts
                <a class="moz-txt-link-rfc2396E" href="mailto:benjamin.watts@psi.ch"><benjamin.watts@psi.ch></a>, Alexander Debus
                <a class="moz-txt-link-rfc2396E" href="mailto:a.debus@hzdr.de"><a.debus@hzdr.de></a>, Nicolas Soler
                <a class="moz-txt-link-rfc2396E" href="mailto:nsoler@cells.es"><nsoler@cells.es></a>, Franz Pöschel
                <a class="moz-txt-link-rfc2396E" href="mailto:f.poeschel@hzdr.de"><f.poeschel@hzdr.de></a>, Emilio Centeno Ortiz
                <a class="moz-txt-link-rfc2396E" href="mailto:ecenteno@cells.es"><ecenteno@cells.es></a><br>
                <b>Subject: </b>Re: [Nexus] HDF5 as NeXus file format<o:p></o:p></span></p>
          </div>
          <div>
            <p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
          </div>
          <div id="divtagdefaultwrapper">
            <p style="margin-left:36.0pt"><span
                style="font-size:12.0pt;color:black">Hi Gabriel,<o:p></o:p></span></p>
            <p style="margin-left:36.0pt"><span
                style="font-size:12.0pt;color:black">   NeXus is
                officially not dependent on HDF5 and we are definitely
                open minded about implementing the NeXus
                <i>data format</i> on <i>file formats</i> other than
                HDF5. We plan to discuss such issues at our
                <a
                  href="https://www.nexusformat.org/Telco_20220426.html"
                  moz-do-not-send="true">next teleconference</a> on
                April 26th and I invite you to join us. Are there
                specific container file formats that you are interested
                in?<o:p></o:p></span></p>
            <p style="margin-left:36.0pt"><span
                style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
            <p style="margin-left:36.0pt"><span
                style="font-size:12.0pt;color:black">Cheers,<o:p></o:p></span></p>
            <p style="margin-left:36.0pt"><span
                style="font-size:12.0pt;color:black">Ben<o:p></o:p></span></p>
            <p class="MsoNormal"
style="mso-margin-top-alt:0cm;margin-right:0cm;margin-bottom:12.0pt;margin-left:36.0pt"><span
                style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
            <div>
              <div class="MsoNormal"
                style="margin-left:36.0pt;text-align:center"
                align="center">
                <span style="font-size:12.0pt;color:black">
                  <hr width="100%" size="0" align="center">
                </span></div>
              <div id="divRplyFwdMsg">
                <p class="MsoNormal" style="margin-left:36.0pt"><b><span
                      style="color:black">From:</span></b><span
                    style="color:black"> NeXus
                    <a class="moz-txt-link-rfc2396E" href="mailto:nexus-bounces@shadow.nd.rl.ac.uk"><nexus-bounces@shadow.nd.rl.ac.uk></a> on behalf
                    of Gabriel Jover Manas via NeXus
                    <a class="moz-txt-link-rfc2396E" href="mailto:nexus@shadow.nd.rl.ac.uk"><nexus@shadow.nd.rl.ac.uk></a><br>
                    <b>Sent:</b> Thursday, 7 April 2022 4:47 PM<br>
                    <b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:nexus@nexusformat.org">nexus@nexusformat.org</a><br>
                    <b>Cc:</b> Gabriel Jover Manas; Nicolas Soler;
                    Emilio Centeno Ortiz<br>
                    <b>Subject:</b> [Nexus] HDF5 as NeXus file format</span><span
                    style="font-size:12.0pt;color:black">
                    <o:p></o:p></span></p>
                <div>
                  <p class="MsoNormal" style="margin-left:36.0pt"><span
                      style="font-size:12.0pt;color:black"> <o:p></o:p></span></p>
                </div>
              </div>
              <div>
                <p class="MsoNormal" style="margin-left:36.0pt"><span
                    style="font-size:12.0pt;color:black">Dear NeXus
                    Users Community,
                    <o:p></o:p></span></p>
                <p style="margin-left:36.0pt"><span
                    style="font-size:12.0pt;color:black">Last NFDI NeXus
                    Workshop was a great opportunity to meet the
                    community and learn from the experience of other
                    scientists and institutions.<o:p></o:p></span></p>
                <p style="margin-left:36.0pt"><span
                    style="font-size:12.0pt;color:black">Here at ALBA we
                    are working on the integration of NeXus files in our
                    data analysis workflows.<o:p></o:p></span></p>
                <p style="margin-left:36.0pt"><span
                    style="font-size:12.0pt;color:black">In this scope
                    we are interested on investigating alternatives to
                    hdf5 as NeXus file format, in terms of slice
                    read/write performance, read-write-many capabilities
                    and convenient reading.<o:p></o:p></span></p>
                <p style="margin-left:36.0pt"><span
                    style="font-size:12.0pt;color:black">Would the
                    community be open to decoupling the data format
                    (NeXus) from the file format (HDF5)?<br>
                    Is there already any effort in the community in this
                    direction?<br>
                    Is anyone else also interested?<o:p></o:p></span></p>
                <p style="margin-left:36.0pt"><span
                    style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
                <p style="margin-left:36.0pt"><span
                    style="font-size:12.0pt;color:black">Best regards,<o:p></o:p></span></p>
                <p style="margin-left:36.0pt"><span
                    style="font-size:12.0pt;color:black">Gabriel<o:p></o:p></span></p>
                <p style="margin-left:36.0pt"><span
                    style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
                <div>
                  <p class="MsoNormal" style="margin-left:36.0pt"><span
                      style="font-size:12.0pt;color:black">--
                      <o:p></o:p></span></p>
                  <div>
                    <div>
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                        style="width:468.0pt;margin-left:36.0pt"
                        width="624" cellspacing="0" cellpadding="0"
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                            <td rowspan="2"
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                              <p><a
                                  href="http://www.albasynchrotron.es/"
                                  target="_blank" moz-do-not-send="true"><span
style="color:windowtext;text-decoration:none"><span
                                      style="color:blue;border:solid
                                      windowtext 1.0pt;padding:0cm"><img
style="width:1.2291in;height:.5729in" id="_x0000_i1025" alt="Image
                                        removed by sender. ALBA
                                        Synchrotron"
                                        src="cid:~WRD0000.jpg"
                                        moz-do-not-send="true"
                                        width="118" height="55"
                                        border="0"></span></span></a><o:p></o:p></p>
                            </td>
                            <td style="width:373.1pt;padding:3.75pt 0cm
                              0cm 0cm" width="497" valign="top">
                              <p class="MsoNormal"><b><span
style="font-size:12.0pt;font-family:"Arial",sans-serif;color:#112E50">Gabriel
                                    Jover-Mañas
                                  </span></b><o:p></o:p></p>
                            </td>
                          </tr>
                          <tr>
                            <td style="width:373.1pt;padding:3.75pt 0cm
                              0cm 0cm" width="497" valign="top">
                              <p class="MsoNormal"><span
                                  style="font-size:9.0pt;font-family:"Arial",sans-serif">Scientific
                                  Data Management<br>
                                  Computing Division </span><o:p></o:p></p>
                            </td>
                          </tr>
                          <tr>
                            <td colspan="2" style="padding:3.75pt 0cm
                              0cm 0cm" valign="top">
                              <p class="MsoNormal"> <o:p></o:p></p>
                            </td>
                          </tr>
                          <tr>
                            <td colspan="2" style="padding:3.75pt 0cm
                              0cm 0cm" valign="top">
                              <p class="MsoNormal"><b><span
                                    style="font-size:10.0pt;font-family:"Arial",sans-serif">ALBA
                                    SYNCHROTRON LIGHT SOURCE</span></b><o:p></o:p></p>
                            </td>
                          </tr>
                          <tr>
                            <td colspan="2" style="padding:3.75pt 0cm
                              0cm 0cm" valign="top">
                              <p class="MsoNormal"><span
style="font-size:9.0pt;font-family:"Arial",sans-serif;color:black"><a
href="http://www.albasynchrotron.es/en/about/coming-to-alba"
                                    target="_blank"
                                    moz-do-not-send="true">Carrer de la
                                    Llum 2-26 | 08290 | Cerdanyola del
                                    Vallès| Barcelona | Spain
                                  </a><br>
                                  (+34) 93 592 4471 </span><o:p></o:p></p>
                            </td>
                          </tr>
                          <tr>
                            <td colspan="2" style="padding:3.75pt 0cm
                              0cm 0cm" valign="top">
                              <p class="MsoNormal"><b><span
                                    style="font-size:9.0pt;color:#112E50"><a
href="http://www.albasynchrotron.es" target="_blank"
                                      moz-do-not-send="true">www.albasynchrotron.es</a></span></b><b><span
style="font-size:7.5pt;color:#112E50"> |
                                  </span></b><b><span
                                    style="font-size:9.0pt;color:#112E50"><a
href="mailto:Gabriel.Jover@cells.es" moz-do-not-send="true"
                                      class="moz-txt-link-freetext">Gabriel.Jover@cells.es
                                    </a>| <a
                                      href="https://www.albasynchrotron.es/en/about/legal-notice"
                                      target="_blank"
                                      moz-do-not-send="true">
                                      legal notice</a> </span></b><o:p></o:p></p>
                            </td>
                          </tr>
                          <tr>
                            <td colspan="2" style="padding:3.75pt 0cm
                              0cm 0cm" valign="top">
                              <p class="MsoNormal">  <o:p></o:p></p>
                            </td>
                          </tr>
                          <tr>
                            <td colspan="2" style="padding:6.0pt 0cm 0cm
                              0cm" valign="top">
                              <p class="MsoNormal"><b><span
                                    style="font-size:8.0pt;color:#8A8A8A">Please,
                                    do not print this e-mail unless it
                                    is absolutely necessary.
                                    <br>
                                  </span></b><span
                                  style="font-size:8.0pt;color:#8A8A8A">Si
                                  heu rebut aquest correu per error, us
                                  informo que pot contenir informació
                                  confidencial i privada i que està
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                            </td>
                          </tr>
                        </tbody>
                      </table>
                      <p class="MsoNormal" style="margin-left:36.0pt"><o:p> </o:p></p>
                    </div>
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                </div>
              </div>
            </div>
          </div>
        </div>
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      <br>
      <fieldset class="moz-mime-attachment-header"></fieldset>
      <pre class="moz-quote-pre" wrap="">_______________________________________________
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