On Fri, Jul 09, 2004 at 10:38:15AM -0500, Thomas Swan wrote:
> visibility issue and how far do you unwind the depth of subtransactions
> or transactions?
>
> BEGIN
> UPDATE A
> SAVEPOINT X
> BEGIN
> BEGIN
> UPDATE B
> BEGIN
> UPDATE C
> ROLLBACK TO SAVEPOINT X
What happens here is that the user will go nuts. We will have a
prominent entry in the docs: "using both nested transactions and
savepoints inside a transaction can cause confusion. We recommend you
stick to one or the other." Or something like that.
(What would really happen: when ROLLBACK TO SAVEPOINT X is executed,
nested transactions created after the SAVEPOINT will be closed.)
So this is another reason why we should use COMMIT to close a nested
transaction: it may refer to a transaction that is already closed
because the user got confused.
--
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
"I can't go to a restaurant and order food because I keep looking at the
fonts on the menu. Five minutes later I realize that it's also talking
about food" (Donald Knuth)