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    <p>I haven't been able to find out much about the render caching
      feature. I am now running all my computer with the render caching
      turned off, so that less memory and swap resources are consumed in
      the computer. It might be intended with this feature to reduce the
      time delay for downloading tiles from a remote server for people
      that are using server based resources but would also have the (in
      your case) less desirable consequence of consuming significant
      amounts of data.<br>
    </p>
    <div class="moz-cite-prefix">On 20/03/19 8:22 PM, Pascale Hutter
      wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:61A44228-339B-4DB6-95A3-4D689D8EE742@hintermannweber.ch">
      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
      Hi Patrick
      <div class=""><br class="">
      </div>
      <div class="">Thanks for you reply! It already helps me a lot, as
        it confirm my impression of the new GIS caching far more data in
        the memory. I was unsure whether this was really the case, as I
        found nothing on the Internet about it. However, if you made the
        same experience this means that there is something different in
        the way it handles raster data.</div>
      <div class=""><br class="">
      </div>
      <div class=""> I will check, if I can change something in the
        settings for rendering, to solve the problem. If I do find
        something, I will let you know. Would be really great if the
        data volume could be decreased this way. Otherwise I can see no
        way how I can use QGIS 3.x for small environmental projects,
        which would be a pity.</div>
      <div class=""><br class="">
      </div>
      <div class="">Thank you for your help!</div>
      <div class=""><br class="">
      </div>
      <div class="">Pascale</div>
      <div class=""><br class="">
        <div class="">
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            -webkit-line-break: after-white-space;" class="">
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              orphans: auto; text-align: start; text-indent: 0px;
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              word-spacing: 0px; -webkit-text-stroke-width: 0px;
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              -webkit-line-break: after-white-space;" class="">
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                    <div class=""><span class="" style="orphans: 2;
                        widows: 2; font-family: Arial;">M. Sc. Biologie</span></div>
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        <br class="">
        <div>
          <blockquote type="cite" class="">
            <div class="">Am 19.03.2019 um 15:15 schrieb Patrick Dunford
              <<a href="mailto:enzedrailmaps@gmail.com" class=""
                moz-do-not-send="true">enzedrailmaps@gmail.com</a>>:</div>
            <br class="Apple-interchange-newline">
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                charset=UTF-8" class="">
              <div text="#000000" bgcolor="#FFFFFF" class="">
                <p class="">I left this question for a few days because
                  I hoped someone with more technical knowledge than me
                  of how Qgis works with this type of data would be able
                  to answer your question. As a user I don't have the
                  same technical insight as one of the developers who
                  may be reading this question and more familiar with
                  data processing in the software.<br class="">
                </p>
                <p class="">I currently work with projects that use
                  large numbers of data layers of raster type, however
                  in my case they are all in files that I have
                  downloaded to my computer and loading locally, rather
                  than any type of data that could be accessed from an
                  online server.</p>
                <p class="">I have found in experience with working with
                  raster layers that Qgis 3 is handling them quite
                  differently from previous versions (I have been using
                  Qgis since 1.8). It was not until version 2.14 that I
                  started working with the projects using these large
                  numbers of raster images, and have been using them
                  through 2.14, 2.16 and 2.18 and now in releases of
                  version 3.</p>
                <p class="">The map projects I am working on cover a
                  part of New Zealand specifically a corridor around
                  6000 kilometres long and about 20 metres wide which is
                  covered by geojpeg rasters varying from 0.4 to 0.1
                  metre per pixel resolution and the size of each raster
                  is generally 4800x7200 pixels.<br class="">
                </p>
                <p class="">The experience I had is that Qgis 3.x
                  appears to be caching a lot more raster data in memory
                  than I saw with 2.x and it seems to be caching every
                  raster in my project, not just the ones that I am
                  displaying at the moment. It uses up the resources in
                  my system a lot faster than 2.x ever did. And if I use
                  larger size raster files, I have seen it run out of
                  resources on the system more than once. <br class="">
                </p>
                <p class="">So in terms of the way it consumes resources
                  for rasters, my experience is more related to the way
                  I see it using up the physical resources on my
                  computer like the physical or virtual memory. I ended
                  up adding more RAM to my system and more swap disk
                  space to help deal with the extra drain on resources
                  that has happened since upgrading to version 3.<br
                    class="">
                </p>
                <p class="">There is a section in the settings dialog
                  that specifically relates to rendering. I'm not
                  completely confident this is the type of situation
                  that would be relevant to your scenario. It may affect
                  my situation more if I spent some time playing with
                  these settings (render caching for example) but it
                  might not be so relevant to you, unless the render
                  caching is causing the software to download a lot of
                  raster data from your WMS server. You could try
                  experimenting with some of those settings.</p>
                <div class="moz-cite-prefix">On 20/03/19 2:08 AM,
                  Pascale Hutter wrote:<br class="">
                </div>
                <blockquote type="cite"
                  cite="mid:CA4EB22E-FB1C-4572-AB18-F7BAF8312BBC@hintermannweber.ch"
                  class="">
                  <meta http-equiv="Content-Type" content="text/html;
                    charset=UTF-8" class="">
                  Hi Patrick
                  <div class=""><br class="">
                  </div>
                  <div class="">Thanks for your interest! Its raster
                    data of aerial images (<a
href="https://shop.swisstopo.admin.ch/de/products/geoservice/swisstopo_geoservices/swisstopoWMS"
                      class="" moz-do-not-send="true">https://shop.swisstopo.admin.ch/de/products/geoservice/swisstopo_geoservices/swisstopoWMS</a>).
                    I often use this for small environmental projects of
                    mine, where I have no budget to buy any additional
                    data. So far the 5’000 Megapixel were enough to work
                    during the whole year. Now it was finished up within
                    a month, although I did much less work. </div>
                  <div class="">I did read, that the whole wms-layer
                    part was newly written for the QGIS version 3.x, so
                    maybe this has something to do with it? </div>
                  <div class=""><br class="">
                  </div>
                  <div class="">Thank you for any kind of help!</div>
                  <div class=""><br class="">
                  </div>
                  <div class="">Pascale</div>
                  <div class=""> </div>
                  <div class=""><br class="">
                    <div class="">
                      <div style="letter-spacing: normal; orphans: auto;
                        text-align: start; text-indent: 0px;
                        text-transform: none; white-space: normal;
                        widows: auto; word-spacing: 0px;
                        -webkit-text-stroke-width: 0px; word-wrap:
                        break-word; -webkit-nbsp-mode: space;
                        -webkit-line-break: after-white-space;" class="">
                        <div style="letter-spacing: normal; orphans:
                          auto; text-align: start; text-indent: 0px;
                          text-transform: none; white-space: normal;
                          widows: auto; word-spacing: 0px;
                          -webkit-text-stroke-width: 0px; word-wrap:
                          break-word; -webkit-nbsp-mode: space;
                          -webkit-line-break: after-white-space;"
                          class="">
                          <div style="letter-spacing: normal; orphans:
                            auto; text-align: start; text-indent: 0px;
                            text-transform: none; white-space: normal;
                            widows: auto; word-spacing: 0px;
                            -webkit-text-stroke-width: 0px; word-wrap:
                            break-word; -webkit-nbsp-mode: space;
                            -webkit-line-break: after-white-space;"
                            class="">
                            <div style="letter-spacing: normal; orphans:
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                                class="">
                                <div class=""><span class=""
                                    style="orphans: 2; widows: 2;
                                    font-family: Arial;">M. Sc. Biologie</span></div>
                                <div class=""><span class=""
                                    style="orphans: 2; widows: 2;
                                    font-family: Arial;">–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––<br
                                      class="">
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                                    Forschung<br class="">
                                    Austrasse 2a | CH-4153 Reinach<br
                                      class="">
–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––<br
                                      class="">
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                                    2; widows: 2;"><font class=""
                                      face="Arial"><a
                                        href="mailto:hutter@hintermannweber.ch"
                                        class="" moz-do-not-send="true">hutter@hintermannweber.ch</a> | <a
href="http://www.hintermannweber.ch/" class="" moz-do-not-send="true">www.hintermannweber.ch</a></font><br
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                                <div class=""><span class=""
                                    style="orphans: 2; widows: 2;"><font
                                      class="" face="Arial">Anwesenheit
                                      im Büro: Mo bis Do</font></span></div>
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                      <blockquote type="cite" class="">
                        <div class="">Am 19.03.2019 um 13:33 schrieb
                          Patrick Dunford <<a
                            href="mailto:enzedrailmaps@gmail.com"
                            class="" moz-do-not-send="true">enzedrailmaps@gmail.com</a>>:</div>
                        <br class="Apple-interchange-newline">
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                          <meta http-equiv="Content-Type"
                            content="text/html; charset=UTF-8" class="">
                          <div text="#000000" bgcolor="#FFFFFF" class="">
                            <p class="">What is the type of data which
                              is within your wms layer. Is this vector
                              or raster type of data?<br class="">
                            </p>
                            <div class="moz-cite-prefix">On 19/03/19
                              12:59 AM, Pascale Hutter wrote:<br
                                class="">
                            </div>
                            <blockquote type="cite"
                              cite="mid:42FA060A-32BF-4855-8C85-09D681F826D1@hintermannweber.ch"
                              class="">
                              <meta http-equiv="Content-Type"
                                content="text/html; charset=UTF-8"
                                class="">
                              Hi there,
                              <div class=""><br class="">
                              </div>
                              <div class="">I’m quite new to QGIS
                                version 3, and was before working with
                                QGIS 2.18. I often use wms-layer, where
                                I purchase a certain data-volume (p. ex.
                                5’000 pixel) to work with. However, with
                                the new QGIS 3.0 this data volume is
                                used up far more quickly. In QGIS 2.18
                                it lasted a lot longer. I was wondering
                                if any of you mades some similar
                                experiences? Do you have any idea, if
                                there is a way to change the settings so
                                the data volume would last longer again?</div>
                              <div class=""><br class="">
                              </div>
                              <div class="">Thank you very much for any
                                suggestions! </div>
                              <div class=""><br class="">
                              </div>
                              <div class="">
                                <div class="">Pascale</div>
                              </div>
                              <div class="">
                                <div class="">
                                  <div style="letter-spacing: normal;
                                    orphans: auto; text-align: start;
                                    text-indent: 0px; text-transform:
                                    none; white-space: normal; widows:
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                                        class="Apple-interchange-newline">
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                                    <br
                                      class="Apple-interchange-newline">
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                                  <br class="Apple-interchange-newline">
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                              <br class="">
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                              <pre class="moz-quote-pre" wrap="">_______________________________________________
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