Updating map causes postgres to hang

[skylarmt]

My server has been importing a daily changeset for several hundred hours now and it started fine but stalled when Postgres started committing the changes. Postgres is hammering a single CPU core at 100% and is reading several hundred megabytes per second from the disk (SSD array).

This makes the project unusable; it's faster to destroy the database and import a fresh planet.pbf than it is to import a single day of updates!