Actually, you can get away pretty well with most cases of searching inside postgres arrays (including joins) thanks to partial indexes. This of course doesn't

Actually, you can get away pretty well with most cases of searching inside postgres arrays (including joins) thanks to partial indexes. This of course doesn't invalidate the point that if you need to perform relational operations on arrays, you need to rethink your database design. AFAIK, the real tradeoff using arrays vs tables is that any update to the array (or other columns) completely rewrite it as Postgres uses MVCC.