Indexer could has an option to force full reindex.

[blu28]

The opengrok-indexer could have an option to force a full reindex from scratch, ignoring the current data and replacing it. This could be useful after an upgrade.

[tulinkry]

I was thinking about this earlier especially in the waves of the RCs we have, but actually is it a good idea to have it if the versions happen not to be compatible?

[vladak]

This certainly needs more thought. I think the idea is to introduce Indexer option (say --full-reindex) ~~and in case the index version is less than the one of the indexer (which can already be checked - see IndexVersion.check())~~, delete the index data and reindex.

For projects it could also remove the project from configuration prior to deleting its index data, reindex and add the project back to configuration however this is probably too much.