Views and performance

I have a two part question dealing with views:

1. If I have a report that repeatedly deletes and recreates views, am I going to cause fragmentation or other "bad" things to happen to my the system tablespace that will eventually degrade overall performance?
2. If a do a join/subselect with a view, as opposed to the base table, will I see a performance increase? Does oracle create a temporary table during the query, and drop it when it finishes? (It seems to behave this way, but I am not certain). I would think that this could yield a performance increase on joins with non-indexed tables; you'd only have to do a single full table scan, as opposed to nested loops of the fulle table. (Doing a nested loop of the view that only contains relavant data would be fine, as every piece of data is what I want) I realize that when a view is created, only the text of the query is stored by oracle, I'm only curious about it's behaviour for the duration of a single select statement execution.

Any hints, ideas?

  -Ky Received on Sun Mar 12 1995 - 06:47:17 CET