Ingest/merger versioning

desiderata.md

Desired behaviour for ingest versioning

Works

Given a work already in the index:

• The same work with a higher transformer version always overrides it
• The same work with the same transformer version and more sources merged in overrides it
• The same work with the same transformer version which have been unlinked from some/all sources overrides it
• The same work with the same transformer version which has been redirected overrides it

Images

Given an image already in the index:

• The same image with a higher transformer version always overrides it
• The same image with the same transformer version but a higher transformer version of any source always overrides it
• The same image with the same transformer version and the same transformer version of all sources, but where any of the sources have more sources merged in, overrides it
• The same image with the same transformer version and a new redirected source overrides it

All but the first point are really just applying the works rules to the works in image.source, but:

1. This can't be done "literally" as the image source works are just work data and do not contain the work state directly
2. The image.source can contain 2 works (canonical and redirected) - but perhaps we can just apply the rules to the canonical work as this will (?) contain the information about redirects?

I think you're right, yes. Do you think that's possible to do within the matcher store (since it already exists)?

Uhm don't think so.. the matcher doesn't know if something gets merged and it also doesn't keep a history. It keeps the current state of the graph but it doesn't keep a record of how it changed, so it doesn't know how many versions of a work have been emitted