Re: Stupid question on Read Committed Isolation Level

On Thu, 29 Jan 2004, Jeroen T. Vermeulen wrote:

> On Thu, Jan 29, 2004 at 01:33:48PM -0400, Marc G. Fournier wrote:
>
> > What happens if I abort on the first transaction?  If I'm reading this
>
> Doesn't matter, because your second transaction doesn't read any of the
> changes you're making there--until (and if) that first one commits.  The
> second transaction simply doesn't care if the the first has been aborted
> or is still running.  It would if the transaction level were READ
> UNCOMMITTED, but with postgres we don't need to worry about that.

Wait, did you read what I had originally posted?  According to the docs
for what I read:

"If two such transactions concurrently try to change the balance of
account 12345, we clearly want the second transaction to start from the
updated version of the account's row"

To me, I read this as the first transaction has not yet committed, but the
second sees its changes ... so if second commitst, and first hasn't yet,
second commits with seconds changes + firsts changes, but what if first
aborts?

----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: scrappy@hub.org           Yahoo!: yscrappy              ICQ: 7615664