As reported on some PR (like angular PR402 - https://github.com/DSpace/dspace-angular/pull/402) I've been experiencing some lag and performance issues. I've just noticed that using other PR besides DSpace master branch (like PR2471 - https://github.com/DSpace/DSpace/pull/2471), the time to serve relationship resources decrease immensely.
http://localhost/server/api/core/relationships took 1.36 sec with the DSpace master branch vs 0.632 sec with PR2471
and a single relationship:
http://localhost/server/api/core/relationships/1 took 0.541 sec with the DSpace master branch vs 0.049 sec with PR2471
Anyone experiencing the same?