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From: Robert Dewar <robert_dewar@my-deja.com>
Subject: Re: Ada Protected Object Turorial #2: Overview of Tasks
Date: 1999/12/21
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In article <385E9343.1D23B0C5@averstar.com>,
  Tucker Taft <stt@averstar.com> wrote:
> Note that most "production quality" database systems operate
> under the presumption that the power cord can be unplugged
> at any moment.  Abort is somewhat less catastrophic than
> that...

Or they run on machines with multiple power cords and multiple
disks, where no one can unplug anything successfully :-)

Clearly if you have a full commit rollback system, then you
can indeed rollback on an abort, but still I find the legitimate
uses of ATC very few. Almost always it is better to have a high
priority task preempt to perform the time critical stuff, and
then cleanly abort the lower priority stuff by polling.


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