the commit rollback thing

[Jay R. Ashworth]

On Fri, Mar 26, 2004 at 10:46:29AM -0500, John Esak wrote:
> > One person has told me that it's tacitly impossible, but you've been known
> > to achieve the impossible before.  :)  I'm curious if there's a way to
> > actually avoid this kind of scenario.
> 
> I think there is a basic understanding among multi-user programmers (you
> obvously being included) that there _are_ simply some situations that can
> not be "covered". Any report is only as good as the absolutley to-the-minute
> data available. If someone changes a record micro/nanoseconds _after_ the
> report has been generated... tough. right?

Well, wrong.  And this is the difference between filePro and a (forgive
me) 'real' DBMS:  Oracle, PostGres, Firebird, Interbase, any of the SQL
DBMS engines will in fact guarantee that all the data is just like you
left it.

>                                            Same has to apply with your
> scneario. It can happen, but the overall design is to try and minimize
> problems that would be created by such a thing. I try never to hold records
> open for longer than the shortest (most atomic limit) that I possibly can...
> I am even so anal (in filePro code) as to try and accomplish everything
> within one then line... :-) I mean there is no difference between a group of
> semicolon'd actions and those actions separated by some blank if lines...
> but I still like to cram such important code onto one line if possible...
> kind of my little stab at not allowing the kinds of things you are getting
> at... which actually could happen, but usually they don't.

Unless the machine dies, in which case DBMS's guarantee the integrity
of your *data* (though transactions may get dropped), but filePro can't
guarantee *anything*.

Cheers,
-- jra
-- 
Jay R. Ashworth                                                jra at baylink.com
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        "They had engineers in my day, too."  -- Perry Vance Nelson