https://mcginniscommawill.com/tags/postgres/ Recent content in Postgres on McGinnis, Will Hugo en-us Mon, 17 Aug 2026 00:00:00 +0000 https://mcginniscommawill.com/posts/2026-08-17-the-billing-bug-you-cant-have/ Mon, 17 Aug 2026 00:00:00 +0000 https://mcginniscommawill.com/posts/2026-08-17-the-billing-bug-you-cant-have/ <p><a href="https://rssemit.com">Emit</a> bills by the email: you prepay for credits, and every send debits one. Which means somewhere in the system there&rsquo;s a number going down as mail goes out, and a nasty question attached to it: what happens when two sends debit the same balance at the same instant?</p> <p>Get this wrong and you either give away free email (annoying) or charge people for mail that never sent (unforgivable). The fix is old, boring database technique, and that&rsquo;s exactly why I want to write it down.</p>