A buddy of mine showed me a cool trick to avoid this
type of problem. What you do is first use SELECT to see
the records in question:
SELECT * from some_table where idx >= 5
Then, once you are staring at the records that came back
(and are sure they are the ones you want to delete),
change SELECT * to DELETE (and change nothing else) and
rerun.
DELETE from some_table where idx >= 5
Pretty hard to get it wrong with this approach ;-)
Or even better, SELECT(*) FROM some_table - that way the developer won't be tempted to skip the step because of too many records scrolling through their screen... not that I learned that from personal experience or anything ;-)
