This was 2005. We had dedicated servers in our own cage. I can't remember if we already had replicas. It seems plausible. But actually spinning up a new one would have required more work and convincing than I wanted to do.

It's probably easy to do if you know it's an issue to begin with. I've run into this scenario before (running sql queries to read data that turned out to lock everything) and it caught me by surprise. Why would a read query cause the database to lock anything? I thought databases did stuff like multiversion concurrency control to make locks like that unnecessary.

Doing large queries on a Postgres standby had the potential to mess up the master, depending on configuration settings.