Reindexing entities when referenced entity fields change is currently supported. It is known to have potentially performance issues in the case that a changed fields triggers reindexing or queueing for reindexing thousands of entities. A switch is provided in configuration to disable this reindexing to avoid such performance issues.
However, disabling reindexing leads to stale content in the index.
An additional improvement could be to add a queue item whenever a field changes, a field that is known to be indexed via an entity reference, and determine the items that need reindexing when processing the queue item. This way loading thousands of entities and looping over them several times is not done right when the entity is saved; instead, it is done in the background.
Active
1.0
General code
That is a very interesting suggestion, thanks!
It is unfortunately a bit more work than I currently have time for, but I’d definitely be willing to review and help with an MR implementing this. Otherwise, I’ll have to see when I have enough time for implementing this myself.