Update datebase

[chen55487]

Hello,

I have successfully set up and run Photon on Debian, and all related functionalities are working as expected. I would like to inquire about the recommended procedure for updating the database in the future (specifically photon-db-latest.tar.bz2 from OpenSearch).

Should I simply download and extract the new archive to overwrite the existing data, or is it necessary to first delete the existing photon_data directory before extracting the updated database files? I want to ensure the update process does not cause any data inconsistencies or application issues.

Thank you in advance for your guidance.

[laem]

I don't know for the OpenSearch version, but for the Elastic it looks like indices are stored in the directory you mentioned, and not being cleaned after an update. The Web says "don't ever erase indices on your own, use Elastic's Web API to ask for cleaning". I don't know more than that, sorry.

[lonvia]

You need to swap out the databases atomically: download and unpack the new version, swap the directories to put the new directory in place of the old one, then restart photon. Now delete the old database. This unfortunately means you need twice the space of the database for updates.

Do not unpack the database in place of the old one. This will lead to corrupted data.

[laem]

Very interesting thanks. That could be mentioned on the Readme I think : #909

[laem]

Asking just in case : is an update possible from an up to date local Overpass DB ? Or is the bridge difficult or impossible to make ?

[laem]

In theory, it should be, since Overpass contains about every OSM data.

[mtmail]

*.pbf files also contain all OSM data. The Overpass database structure is too different. And running queries against the API to construct OSM places, then merging them would be too slow to be usable.

[laem]

Even just for updates ? I understand that deriving a search index as a whole from overpass is too costly, but what about updates ?

[lonvia]

Photon is derived from a Nominatim database that's something completely different from Overpass. If you want to have a regularly updated Photon database, set up Nominatim with updates and enable updates in Photon as described in the README.

With the new json dumps, there is in theory a venue to provide also json updates but that falls under the category of premium features, i.e. this will only happen if somebody funds development and running the production server.