On Fri, 9 Jul 2004, Mike Rylander wrote: > Nested transactions and savepoints serve two different purposes. They have > some overlap, but for the most part solve two distinct problems.
Then show some examples that illustrait the difference. So far all examples shown that uses subtransactions could just as well have been written using savepoints. I don't agree that they have two different purposes. > I don't think so, especially as there has been some talk of implimenting > savepoints as a subset of nested transactions. It is not a subset. It's the other way around. Nested transactions are a subset of savepoints Savepoints have more possibilities, you can invalidate older savepoints then the last (with subtransactions you can only commit/rollback the last). If you don't use that then it's exactly the same as subtransactions. The only "feature" subtransactions have that savepoints doesn't is the lack of names. Every savepoint have a name. If we want an extension it could be to get the database to generate a fresh savepoint name. The client can of course also generate unique savepoint names if it want. That subtransactions do more than savepoints is just smoke an mirrors. So far there have been no example to validate that point of view, and I don't think there will be any. If anyone know of something that you can do with subtransactions and not with savepoints, please speak up. -- /Dennis Björklund ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
