At one interview I was asked about VIEWs. I answered honestly: in real projects I had barely run into them; for aggregates it is safer to keep a separate table. One of the interviewers said, “You understand nothing about VIEWs,” and everyone laughed.
Source: [Dev.to](https://dev.to/aleksander_frolov/one-cast-made-a-view-13x-slower-in-postgresql-so-i-benchmarked-mysql-84-against-postgresql-17-11en)