[Ruby] Dumb ActiveRecord question

[Chris]

> This made a major difference in the performance of the app. What was an
> 85-second query dropped to  milliseconds. The SQL generated by the
> associations I had mapped was causing sequential scans across a very large
> table. While the solution I came up with works, right now I'm inclined to
> think that it's more likely I'm not using ActiveRecord correctly than
> ActiveRecord is doing something degenerate. A little quality time with the
> docs and a beer may perhaps provide some enlightenment. ;-)

What database is this?

Chris