I am pretty sure that just running UPDATE is enough. If an UPDATE happens to get stuck waiting for a lock it is re-evaluated. EDIT: Found where it is explained

I am pretty sure that just running UPDATE is enough. If an UPDATE happens to get stuck waiting for a lock it is re-evaluated. EDIT: Found where it is explained in the documentation. I do not see why this should not also apply to JSON. http://www.postgresql.org/docs/9.3/static/transaction-iso.html#XACT-READ-COMMITTED http://www.postgresql.org/docs/9.3/static/transaction-iso.ht...