advise against using Postgresql 12 and Postgis 3

See also #1677

diff --git a/docs/admin/Installation.md b/docs/admin/Installation.md
index d6232c8b4138baa8308413e3ae1994c18d640a6f..0dd6579b98cb1fa734e22d66d898a6486993eceb 100644 (file)
--- a/docs/admin/Installation.md
+++ b/docs/admin/Installation.md
@@ -35,8 +35,8 @@ For compiling:
 
 For running Nominatim:
 
-  * [PostgreSQL](https://www.postgresql.org) (9.3 or later)
-  * [PostGIS](https://postgis.org) (2.2 or later)
+  * [PostgreSQL](https://www.postgresql.org) (9.3 - 11)
+  * [PostGIS](https://postgis.org) (2.2 - 2.5)
   * [Python 3](https://www.python.org/)
   * [Psycopg2](https://initd.org/psycopg)
   * [PHP](https://php.net) (7.0 or later)
@@ -44,6 +44,10 @@ For running Nominatim:
   * PHP-intl (bundled with PHP)
   * a webserver (apache or nginx are recommended)
 
+!!! danger "Important"
+    Postgresql 12+ and Postgis 3.0+ are known to cause performance issues. They are
+    not recommended for a production installation at the moment.
+
 For running continuous updates:
 
   * [pyosmium](https://osmcode.org/pyosmium/) (with Python 3)