+SQL statements should be executed from the PostgreSQL commandline. Execute
+`psql nominatim` to enter command line mode.
+
+## 3.3.0 -> master
+
+### 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
+
+Previously database connection setting (`CONST_Database_DSN` in `settings/*.php`) had the format
+
+ * (simple) `pgsql://@/nominatim`
+ * (complex) `pgsql://johndoe:secret@machine1.domain.com:1234/db1`
+
+The new format is
+
+ * (simple) `pgsql:dbname=nominatim`
+ * (complex) `pgsql:dbname=db1;host=machine1.domain.com;port=1234;user=johndoe;password=secret`
+
+### Natural Earth country boundaries no longer needed as fallback
+
+```
+DROP TABLE country_naturalearthdata;
+```
+
+Finally, update all SQL functions:
+
+```sh
+./utils/setup.php --create-functions --enable-diff-updates --create-partition-functions
+```
+
+### Configurable Address Levels
+
+The new configurable address levels require a new table. Create it with the
+following command:
+
+```sh
+./utils/update.php --update-address-levels
+```
+
+## 3.1.0 -> 3.2.0
+
+### New reverse algorithm
+
+The reverse algorithm has changed and requires new indexes. Run the following
+SQL statements to create the indexes:
+
+```
+CREATE INDEX idx_placex_geometry_reverse_lookupPoint
+ ON placex USING gist (geometry)
+ WHERE (name is not null or housenumber is not null or rank_address between 26 and 27)
+ AND class not in ('railway','tunnel','bridge','man_made')
+ AND rank_address >= 26 AND indexed_status = 0 AND linked_place_id is null;
+CREATE INDEX idx_placex_geometry_reverse_lookupPolygon
+ ON placex USING gist (geometry)
+ WHERE St_GeometryType(geometry) in ('ST_Polygon', 'ST_MultiPolygon')
+ AND rank_address between 4 and 25 AND type != 'postcode'
+ AND name is not null AND indexed_status = 0 AND linked_place_id is null;
+CREATE INDEX idx_placex_geometry_reverse_placeNode
+ ON placex USING gist (geometry)
+ WHERE osm_type = 'N' AND rank_search between 5 and 25
+ AND class = 'place' AND type != 'postcode'
+ AND name is not null AND indexed_status = 0 AND linked_place_id is null;
+```
+
+You also need to grant the website user access to the `country_osm_grid` table:
+
+```
+GRANT SELECT ON table country_osm_grid to "www-user";
+```
+
+Replace the `www-user` with the user name of your website server if necessary.
+
+You can now drop the unused indexes:
+
+```
+DROP INDEX idx_placex_reverse_geometry;
+```
+
+Finally, update all SQL functions:
+
+```sh
+./utils/setup.php --create-functions --enable-diff-updates --create-partition-functions
+```