X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/f8f20899a35863876c8dd552f4639d681102ee60..77510f4a3bb7a40c85d27ed5c71b20ef79a3aa83:/docs/admin/Installation.md?ds=inline

diff --git a/docs/admin/Installation.md b/docs/admin/Installation.md
index 8c4c670b..d7d35b7e 100644
--- a/docs/admin/Installation.md
+++ b/docs/admin/Installation.md
@@ -45,6 +45,7 @@ For running Nominatim:
   * [PostgreSQL](https://www.postgresql.org) (9.6+ will work, 11+ strongly recommended)
   * [PostGIS](https://postgis.net) (2.2+ will work, 3.0+ strongly recommended)
   * [Python 3](https://www.python.org/) (3.6+)
+  * [Python Typing Extensions](https://github.com/python/typing_extensions)
   * [Psycopg2](https://www.psycopg.org) (2.7+)
   * [Python Dotenv](https://github.com/theskumar/python-dotenv)
   * [psutil](https://github.com/giampaolo/psutil)
@@ -89,8 +90,7 @@ your `postgresql.conf` file.
     work_mem = (50MB)
     effective_cache_size = (24GB)
     synchronous_commit = off
-    checkpoint_segments = 100 # only for postgresql <= 9.4
-    max_wal_size = 1GB # postgresql > 9.4
+    max_wal_size = 1GB
     checkpoint_timeout = 10min
     checkpoint_completion_target = 0.9
 
@@ -158,6 +158,17 @@ make
 sudo make install
 ```
 
+!!! warning
+    The default installation no longer compiles the PostgreSQL module that
+    is needed for the legacy tokenizer from older Nominatim versions. If you
+    are upgrading an older database or want to run the
+    [legacy tokenizer](../customize/Tokenizers.md#legacy-tokenizer) for
+    some other reason, you need to enable the PostgreSQL module via
+    cmake: `cmake -DBUILD_MODULE=on ../Nominatim`. To compile the module
+    you need to have the server development headers for PostgreSQL installed.
+    On Ubuntu/Debian run: `sudo apt install postgresql-server-dev-<postgresql version>`
+
+
 Nominatim installs itself into `/usr/local` per default. To choose a different
 installation directory add `-DCMAKE_INSTALL_PREFIX=<install root>` to the
 cmake command. Make sure that the `bin` directory is available in your path