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<p>I looked through bunch of those, I don't now if to call it
decent.</p>
<p>Seems the common themes are:</p>
<p>1. some or all member ways exist and they have tags from the
relation. I assume people were simplifying multipolygons into
simple polygons/areas and forgot to delete.</p>
<p>2. all ways are gone. Hard to guess, but mostly it seems like
fixing old data/imports.<br>
</p>
<p>3. Relation was created but never had any members. User's error.<br>
</p>
<p>4. lot of times original multipolygon didn't even have any other
tags to begin with and someone was fixing it by re-repurposing the
ways for something else.<br>
</p>
<p>5. for turn restrictions or public transport, it's hard to guess,
but it seemed those people knew what they are doing and just
forgot to delete.</p>
<p><br>
</p>
<p>I'd say all are useless leftovers, but if there is still anything
useful people can keep digging through
<a class="moz-txt-link-freetext" href="https://storage.googleapis.com/osm_cleanup/emptyRelation.csv">https://storage.googleapis.com/osm_cleanup/emptyRelation.csv</a> and
undelete the particular relation id if they want to restore the
original object.<br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 19.4.21 3:44 , Mateusz Konieczny via
talk wrote:<br>
</div>
<blockquote type="cite" cite="mid:MYd4dhg--B-2@tutanota.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div>Thanks for taking care of asking before making an edit!<br>
</div>
<div><br>
</div>
<div>------------------------<br>
</div>
<div><br>
</div>
<div>Have you reviewed at least some decent sample of this objects
to check is<br>
</div>
<div>it going to remove valid data or hide more serious problems?<br>
</div>
<div><br>
</div>
<div>Sometimes such things are indicator of broken imports or not
noticed<br>
</div>
<div>vandalism and removing them would just hide this problems.<br>
</div>
<div><br>
</div>
<div>Sometimes it is perfectly fine to purge such data
automatically.<br>
</div>
<div><br>
</div>
<div>------------------------<br>
</div>
<div><br>
</div>
<div>Also, I remember a tool that was able to show old geometries
of an object.<br>
</div>
<div>Sadly I am unable to track it down.<br>
</div>
<div><br>
</div>
<div>Unlike attic data where it is necessary to select location
and date manually it<br>
</div>
<div>was enough to provide object id.<br>
</div>
<div><br>
</div>
<div>It would be very useful to review relations from (1) <br>
</div>
<div><br>
</div>
<div>Apr 18, 2021, 18:43 by <a class="moz-txt-link-abbreviated" href="mailto:machyna@gmail.com">machyna@gmail.com</a>:<br>
</div>
<blockquote class="tutanota_quote" style="border-left: 1px solid
#93A3B8; padding-left: 10px; margin-left: 5px;">
<div dir="ltr">
<div>Hi everyone,<br>
</div>
<div><br>
</div>
<div>I had an idea that came during my work on a buildings
import. I would like to clear/fix improperly
created/deconstructed relations. This would include:<br>
</div>
<div><br>
</div>
<div>1) Remove relations that have no members, nor are
members of a relation themselves. <br>
</div>
<div><br>
</div>
<div>
<div>[out:json][timeout:250];<br>
</div>
<div>relation[type](if: count_members() == 0);<br>
</div>
</div>
<div>
<div>rel(br) -> .parents;<br>
</div>
<div>(._; - rel(r.parents););<br>
</div>
<div>out ids;<br>
</div>
</div>
<div><br>
</div>
<div>2) Remove type=multipolygon from ways.<br>
</div>
<div><br>
</div>
<div>
<div>[out:json][timeout:250];<br>
</div>
<div>way[type=multipolygon];<br>
</div>
<div>out ids;<br>
</div>
</div>
<div><br>
</div>
<div><br>
</div>
</div>
</blockquote>
<div><br>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
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