I too was 'taken aback' by the blanket statement Refresh your development databases nightly. Also the mention of poorly performing queries (what ever happened to the QA/Perfromance Test environment (or database) that may be refreshed nightly (more like a production 'fix' environment). Multiple toered software development environments wer the standard once ... now with the ever increasing performance and decreasing cost of servers there is almost no reason why an organization cannot have a multi-tiered software development environment.

• Development
• Test
• QA/Performance Test
• Production 'fix'
• Production

After all if you can hire a enought developers to warrant software source code control system then you probably need a more segregated environment !