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Hello,<br>
<br>
I would like to learn more about how the PostGIS development
community thinks about old major versions of PostgreSQL.<br>
<br>
Specifically, I'm curious to hear a little more elaboration on this
part of the PostGIS policy:<br>
<br>
<blockquote type="cite">We may on occasion introduce compile support
for a newer PostgreSQL major version in the previous micro version
to allow easier PostgreSQL pg_upgrade migrations. ... While the
PostGIS version may work on lower versions of PostgreSQL, GEOS,
GDAL, and Proj, enhanced features may be disabled on the lower
versions.</blockquote>
<br>
<a class="moz-txt-link-freetext"
href="https://postgis.net/eol_policy/" moz-do-not-send="true">https://postgis.net/eol_policy/</a><br>
<br>
I also notice that the support matrix says:<br>
<br>
<blockquote type="cite">As a general rule, the PostGIS Project
Steering committee tries to maintain support of PostGIS for at
least two versions of PostgreSQL.</blockquote>
<br>
<a class="moz-txt-link-freetext"
href="https://trac.osgeo.org/postgis/wiki/UsersWikiPostgreSQLPostGIS"
moz-do-not-send="true">https://trac.osgeo.org/postgis/wiki/UsersWikiPostgreSQLPostGIS</a><br>
<br>
I see that PostGIS maintains stable branches for a number of years.
I can't quite tell, but the statements above read to me like the
latest versions of PostGIS aren't really tested with old versions of
PostgreSQL. It sounds like you introduce compiler support for the
purpose of upgrades, but the PostGIS development community doesn't
spend much effort looking at PostGIS 3.1 on PostgreSQL 10 (for
example) - beyond making sure it compiles successfully.<br>
<br>
If I'm reading this right, then when a heavy PostgreSQL v10 user
loads the latest PostGIS code across wide fleets of PostgreSQL v10
systems, then they should expect to be on the cutting edge of that
configuration, and they would likely be the first reporters of
issues unique to running the latest PostGIS release on old
PostgreSQL code.<br>
<br>
It might be "safer" for them to stick with PostGIS 2.4 stable
releases on their PostgreSQL 10 fleet, and upgrade PostGIS around
the same time as when they upgrade to the latest major version of
PostgreSQL? (Which should happen within the next year, since PG 10
only has about a year of official lifetime remaining, similar to
PostGIS 2.4.)<br>
<br>
But maybe I'm reading too much into this policy and the maintenance
of stable branches, and maybe the PostGIS community would encourage
everyone to run the latest available PostGIS major version even on
very old versions of PostgreSQL? Also, the actual risk of issues
with running recent PostGIS code against really old PostgreSQL
versions might not be that high in practice.<br>
<br>
I'm a bit out of my depth here, and I'm looking for thoughts from
folks who know a bit more about this than me. :)<br>
<br>
Thanks,<br>
Jeremy<br>
<br>
<pre class="moz-signature" cols="72">--
Jeremy Schneider
Database Engineer
Amazon Web Services</pre>
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