Hi
>Why just do a plain update, relying on row level locking to serialize requests properly, and then just do an insert where not exists? Is there value in doing the delete? I don't see it.
This is an option. How to do update+insert in 9+ in SQL ? Or should plpgsql procedure created for this ?
After insert if other process inserts same key value, transaction
still ways. Should manual locking used or is there better method.