One of PostgreSQL's best features is transactional DDL: You can run "drop table" etc. in a transaction and roll back afterwards. This has saved me a few times.

One of PostgreSQL's best features is transactional DDL: You can run "drop table" etc. in a transaction and roll back afterwards. This has saved me a few times. It also makes it trivial to write atomic migration scripts: Rename a column, drop a table, update all the rows, whatever you want -- it will either all be committed or not committed at all. Surprisingly few databases support this. (Oracle doesn't, last I checked.)