Re: Multiple update problem

From: Mungo Henning <mungoh_at_itacs.strath.ac.uk>
Date: Thu, 21 May 1998 09:03:35 +0100
Message-ID: <3563DFD7.6C670AC8_at_itacs.strath.ac.uk>


[Quoted] [Quoted] Thanks for the reply Thomas, but I'm still curious...

Thomas Kyte wrote:
[multiple update scenario snipped]
>
> >I'm thinking of the following (separate) scenarios: the past is to the
> >left
> >of the line, the future to the right:
> >
> > UserA:update UserB:insert UserA:commit UserB:commit
>
> If userA updates 10 to 90, UserB's insert will BLOCK on the unique index entry.
When userA performs the update, the index will be modified. But I was [Quoted] under the impression that for read-consistency userB should not be aware that another user is amending the table until the amendments [Quoted] are committed? I'm quite willing to believe that it's my impression of Oracle that's wrong, but can you set me straight please?

[Quoted] When you say "BLOCK" do you mean that the insert will be suspended [Quoted] pending the lock? What would happen if userA then altered the same [Quoted] record (whose value is now ninety) to eighty without committing - would the block be released?

TIA
Mungo Henning Received on Thu May 21 1998 - 10:03:35 CEST

Original text of this message