Subject Re: 3 * 1/3 = 0 ??? csswa 2002-09-02T18:38:21Z
> I always thought this was true
>
> (1/3)*3 = 1
>
> But Interbase and Firebird (and probably all the other RDBMSs) say
> this equals 0.
... etc.

Regarding Dialect 3 treating integer results < 1 as zero, here is
message 12832 verbatim which explains why. You may care to follow
that earlier, lengthy, '\$5 calculator' thread
thereabouts to save rehashing it now.

Note that when Helen is conspicuously absent from a busy thread
there is good reason, e.g. 1) it has been flogged to death in earlier
posts; or 2) it's all there if one cared to RTFM; or 3) ignorance
mobs, mobs go on witch hunts, and ... well, it just so happens that
Helen owns a pointy hat. However, in this instance I believe the

-Andrew Ferguson
<GGZZZZTT, cloaking device reactivated>

From: "csswa" <csswa@y...>
Date: Fri May 31, 2002 11:55 am
Subject: divisions - final final, really really!

'One L' gets the final word, and as usual she brings a state of zen-
like calm to this crazy, mixed-up world.

It's not a bug but the result of purer mathematical implementation.

BTW, having no further need for my \$5 calculator, it now returns to
the back of the drawer. In fact I owe IBPhoenix \$5. :-)

Regards,
Andrew Ferguson
-- We've got what it takes to take what you've got.

-----

>Why the behaviour difference between dialects???

Because of the difference in the treatment and storage of numbers.
D.3 regards all numbers as expressible as 64-bit integer, D.1 as 32-
bit (like MSSQL and Oracle).

Because of this, new rules apply...
In D.3 (and, I think, in D.1 columns which were created on ODS10, not
certain about that though) the result of a division between two
integers is an integer. (There is actually a mathematical
justification for this which I *think* was explained by
Claudio during the "Klapperich bug" episode). In contrast, the
result of such a division in D.1 and lower IB's (and also MSSQL and
Oracle and probably PG as well, which don't have true 64-bit integer
support) results in a single or a double, depending on the scale of
the integers involved.