It's been a while but I'm pretty sure that's exactly what we ended up doing. The advisory lock was because downstream logic required returning the primary key —

It's been a while but I'm pretty sure that's exactly what we ended up doing. The advisory lock was because downstream logic required returning the primary key — basically https://en.m.wikipedia.org/wiki/Double-checked_locking https://en.m.wikipedia.org/wiki/Double-checked_locking. Thanks for sharing.