This page describes database migrations necessary to update existing databases
to newer versions of Nominatim.
-SQL statements should be executed from the postgres commandline. Execute
+SQL statements should be executed from the PostgreSQL commandline. Execute
`psql nominatim` to enter command line mode.
+## 3.4.0 -> master
-## 3.2.0 -> master
+### New Wikipedia/Wikidata importance tables
+
+The `wikipedia_*` tables have a new format that also includes references to
+Wikidata. You need to update the computation functions and the tables as
+follows:
+
+ * download the new Wikipedia tables as described in the import section
+ * reimport the tables: `./utils/setup.php --import-wikipedia-articles`
+ * update the functions: `./utils/setup.php --create-functions --enable-diff-updates`
+ * compute importance: `./utils/update.php --recompute-importance`
+
+The last step takes about 10 hours on the full planet.
+
+## 3.3.0 -> 3.4.0
+
+### Reorganisation of location_area_country table
+
+The table `location_area_country` has been optimized. You need to switch to the
+new format when you run updates. While updates are disabled, run the following
+SQL commands:
+
+```sql
+CREATE TABLE location_area_country_new AS
+ SELECT place_id, country_code, geometry FROM location_area_country;
+DROP TABLE location_area_country;
+ALTER TABLE location_area_country_new RENAME TO location_area_country;
+CREATE INDEX idx_location_area_country_geometry ON location_area_country USING GIST (geometry);
+CREATE INDEX idx_location_area_country_place_id ON location_area_country USING BTREE (place_id);
+```
+
+## 3.2.0 -> 3.3.0
### New database connection string (DSN) format