Depends on your goals. If you're a software engineer, it won't make a difference, just send two queries to the DB and combine the results before sending them off. If you're an analyst, you'll often get repeated ad-hoc requests. If you have to run 2 queries, then stitch them together, each time you are asked for a report, you're wasting tons of (really boring) time. Even if you ultimately create some code to run and stitch the results together for you, it's just faster and easier to write 1 query wherever possible. Just let the database do the work!