* The included version of the GPX importer is slow and/or completely inoperable. You should consider using [the high-speed GPX importer](https://git.openstreetmap.org/gpx-import.git/).
* Make sure you generate the i18n files and precompile the production assets: `RAILS_ENV=production rake i18n:js:export assets:precompile`
* Make sure the web server user as well as the rails user can read, write and create directories in `tmp/`.
-* If you want to use diff replication then you will need to install the shared library special SQL functions for the `xid_to_int4` function, for which there is no pure SQL alternative. (See the bottom of [INSTALL.md](INSTALL.md))
+* If you want to use diff replication then you might want to consider installing the shared library special SQL functions for the `xid_to_int4` function. A pure SQL version is available, but may become a performance issue on large databases with a high rate of changes. Note that you will need a version of PostgreSQL < 9.6 (yes, _less than_) to use `xid` indexing, whether pure SQL or shared library.
* If you expect to serve a lot of `/changes` API calls, then you might also want to install the shared library versions of the SQL functions.