osm2pgsql/docs/migrations.md

Migrations between versions

Some osm2pgsql changes have slightly changed the database schema it expects. If updating an old database, a migration may be needed. The migrations here assume the default planet_osm prefix.

0.88.0 z_order changes

0.88.0 z_order logic was changed, requuiring an increase in z_order values. To migrate to the new range of values, run

UPDATE planet_osm_line SET z_order = z_order * 10;
UPDATE planet_osm_roads SET z_order = z_order * 10;

This will not apply the new logic, but will get the existing z_orders in the right group of 100 for the new logic.

If not using osm2pgsql z_orders, this change may be ignored.

0.87.0 pending removal

0.87.0 moved the in-database tracking of pending ways and relations to in-memory, for an increase in speed. This requires removal of the pending column and a partial index associated with it.

ALTER TABLE planet_osm_ways DROP COLUMN pending;
ALTER TABLE planet_osm_rels DROP COLUMN pending;

32 bit to 64 bit ID migration

Old databases may have been imported with 32 bit node IDs, while current OSM data requires 64 bit IDs. A database this old should not be migrated, but reloaded. To migrate, the type of ID columns needs to be changed to bigint.