Sharing data to other users?

The performance-related effects of the trigger(s) could be minimal. Depends upon a few things.

If you don’t know how the index design would need to support this technique, you might find yourself wanting to benefit from an experienced database person with or without this trigger-based technique.

You could also implement what you are interested in here with event scripts (and still have your database performance problems if you don’t know how to index well…).