Re: schema/db design wrt performance

On Thu, 2003-01-16 at 09:39, Andrew Sullivan wrote:
> On Thu, Jan 16, 2003 at 08:34:38AM -0600, Ron Johnson wrote:
> > On Thu, 2003-01-16 at 08:20, Andrew Sullivan wrote:
>
> > > If a user has multiple connections and charges things to the same
> > > account in more than one connection at the same time, the
> > > transactions will have to be processed, effectively, in series: each
> > > one will have to wait for another to commit in order to complete.
> >
> > This is true even though the default transaction mode is
> > READ COMMITTED?
>
> Yes.  Remember, _both_ of these are doing SELECT. . .FOR UPDATE.
> Which means they both try to lock the corresponding record.  But they
> can't _both_ lock the same record; that's what the lock prevents.

Could BEFORE INSERT|UPDATE|DELETE triggers perform the same
functionality while touching only the desired records, thus
decreasing conflict?

--
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| Ron Johnson, Jr.     mailto:ron.l.johnson@cox.net          |
| Jefferson, LA  USA   http://members.cox.net/ron.l.johnson  |
|                                                            |
| "Basically, I got on the plane with a bomb. Basically, I   |
|  tried to ignite it. Basically, yeah, I intended to damage |
|  the plane."                                               |
|    RICHARD REID, who tried to blow up American Airlines    |
|                  Flight 63                                 |
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