Just a opnion!
Overall, Im not much fan of PDI DB repo. In the past a got a bad experience with it where as the repo grows it was becoming slower (to the point where it was impossible).
Ok it was far down the 3.x and 4.x and from that time to these days a have been using file system repo for most of situations.
The best thing from a fs repo is that you can use any version control to deal with your maps (ktr,kjb) and can apply a CI/CD in a farly simple way.
Also, if you really whats a DB repo (if you intent to go carte, db is probably a better choice) you could try a postgresql or a mysql.