One consequence of that is that: > Multiple instances per device are almost a must. Isn't actually unproblematic in OLTP, because it increases the number of j

One consequence of that is that: > Multiple instances per device are almost a must. Isn't actually unproblematic in OLTP, because it increases the number of journal writes that need to be flushed. With a single instance group commit can amortize the write cache flush costs much more efficiently than with many concurrent instances all separately doing much smaller group commits.