Trigger memory use
If you've used some of the suggestions here to group your database commits into larger chunks, you might notice an expected downside to that: running out of memory at commit time. The issue is that if the table you're changing has an AFTER trigger on it, each statement due to trigger is inserted into an in-memory list. If there are a large number of them, perhaps due to a bulk loading job, it's possible to run out of the amount of memory on the system (or reach the limit for your user account) before the transaction can complete. Be careful when combining AFTER triggers with batch commits.
