Merge remote-tracking branch 'upstream/master'

[nominatim.git] / docs / admin / Migration.md

diff --git a/docs/admin/Migration.md b/docs/admin/Migration.md
index 6ae7a9272c73b9ce55a3dfd6530668a5f493b7d1..c5a05d9afec79b93f5c81439847071c1da92c852 100644 (file)
--- a/docs/admin/Migration.md
+++ b/docs/admin/Migration.md
@@ -3,11 +3,27 @@
 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.
 
+## 3.3.0 -> master
 
-## 3.2.0 -> 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