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Nominatim/docs/Migration.md
2017-08-19 19:37:06 +02:00

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Database Migrations
===================
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
`psql nominiatim` to enter command line mode.
3.0.0
-----
### Postcode Table
A new separate table for artificially computed postcode centroids was introduced.
Migration to the new format is possible but **not recommended**.
* create postcode table and indexes, running the following SQL statements:
CREATE TABLE location_postcode
(place_id BIGINT, parent_place_id BIGINT, rank_search SMALLINT,
rank_address SMALLINT, indexed_status SMALLINT, indexed_date TIMESTAMP,
country_code varchar(2), postcode TEXT,
geometry GEOMETRY(Geometry, 4326));
CREATE INDEX idx_postcode_geometry ON location_postcode USING GIST (geometry);
CREATE UNIQUE INDEX idx_postcode_id ON location_postcode USING BTREE (place_id);
CREATE INDEX idx_postcode_postcode ON location_postcode USING BTREE (postcode);
GRANT SELECT ON location_postcode TO "www-data";
* add postcode column to location_area tables with SQL statement:
ALTER TABLE location_area ADD COLUMN postcode TEXT;
* reimport functions
./utils/setup.php --create-functions --enable-diff-updates --create-partition-functions
* create appropriate triggers with SQL:
CREATE TRIGGER location_postcode_before_update BEFORE UPDATE ON location_postcode
FOR EACH ROW EXECUTE PROCEDURE postcode_update();
* populate postcode table (will take a while):
./utils/setup.php --calculate-postcodes --index --index-noanalyse
This will create a working database. You may also delete the old artificial
postcodes now. Note that this may be expensive and is not absolutely necessary.
The following SQL statement will remove them:
DELETE FROM place_addressline a USING placex p
WHERE a.address_place_id = p.place_id and p.osm_type = 'P';
ALTER TABLE placex DISABLE TRIGGER USER;
DELETE FROM placex WHERE osm_type = 'P';
ALTER TABLE placex ENABLE TRIGGER USER;