Re: Informix vs. Sybase vs. Oracle vs. (gasp) MS SQL Server

Jean-Marc van Leerdam wrote:

> Anthony Mandic wrote:
>
> > Only if that lock was held for longer than it ought to have been.
>
> Regardless, I think one should NOT be troubled by things being done to
> records that are of no concern to that user. With PLL you can (and
> will) be troubled in such a way.

	Except in the case where one user has one row locked with RLL
	and another users want a summery of all rows including the
	locked one. Then you have to introduce further mechanisms to
	overcome this. But no lock, implies no problem and no further
	complexity.

> I think, even in a set-based thinking environment, it should not be
> the database that causes these problems. I strongly support the
> availability of RLL (even if sometimes PLL would be a performance
> advantage, I still want the option of RLL without cumbersome tricks or
> fake identifiers).

        I agree.

> > These should be fast. If there are a lot of them in one hit, I'd
> > consider rethinking the approach used to design the app that
> > does this. The implication here is that the app may be far too
> > complex, thus being more vulnerable to problems. Keeping it
> > simple never hurts.
>
> Just 'blaming' the apps complexity is no real solution too, I think we
> should see the apps complexity and way of operating as a given.
> Just because a RDBMS acts on sets and likes set-like operations, that
> doesn't mean the customer does the same or should be trained to do so
> (that sets us back some 30 years, when we still wanted to adapt the
> users to the programs instead of the other way around).

	I think at this point I'd start to think of the meaning of
	relational. You could select one row initially and then
	sets of related rows.

> IMHO a RDBMS should let the user operate on rows, completely
> independent of the status and concurrent use of 'nearby' rows by other
> users.
> That implies RLL in my opinion.
>
> Also, in a set-based thinking environment: why is some element
> 'closer' to another element than another element, and why does
> modifying one element influence the success of modifications to SOME
> other elements but not to ALL other elements?
> Elements in a set should IMO be independent objects.

	I'd think relational again. Thus elements in a set are
	independant but related.

-am Received on Fri Nov 28 1997 - 00:00:00 CET