ScottPletcher (1/24/2013)
Of course indexing requires persisting. I thought everyone was clear on that.
But you claimed, in your first quote above, there was no (never a) need to persist except to index. That's simply not true. Even if a computed column is not indexed in any way, there are times when it's still worthwhile to persist it to avoid re-computing it.
Right, OK, I see where the confusion is now, even if I don't know where you think I said there's never a need to persist a computed column, except to index it. I certainly didn't claim that, hence why I pointed out that you misunderstood my comment. If that was what I wanted to say, I would have said:
"There's no need to make the column persisted except to index it"
But what I said (and highlighted again after your comment) was:
There's no need to make the column persisted prior to indexing it.
As in, there's no requirement to persist the column before indexing it.