Re: insert to projection

From: paul c <>
Date: Fri, 04 Sep 2009 21:10:56 GMT
Message-ID: <Anfom.42731$Db2.33947_at_edtnps83>

Tegiri Nenashi wrote:
> On Sep 4, 10:52 am, paul c <> wrote:
>> Tegiri Nenashi wrote:

>>> I suggest that the idea that we focus on basic relational algebra
>>> operators, figure out which updates of these are legitimate, then
>>> leverage this knowledge for complex view updates is fundamentally
>>> wrong. Consider a "pivot" view:
>>> ...
>> Since when does RA have updates?

> I understood this thread was about view updates. Projection view to be
> exact.

Yes, there is no point in trying to be so precise that the people in the audience here who actually have some influence over the evolution of dbms's, at least in the way they choose to use dbms's, have no idea what the topic really is. I think "update" is a language notion, not an algebra notion, but a lot of people seem to assume it's the latter. If insert to projection means asserting an implication, all you need is a language that allows you to assert an implication so I say why not play the ball where it lies?

(For somebody like me who started programming with some pretty arcane physical file systems, the word "update" itself is a big problem, being either too casual for any meaningful insight ora misleading sop to 1959 file system lingo which can be dangerous because of what the word meant then, such as the inability to "update" a physical key with those file systems, some people still think keys have something to do with updating when a language that follows RA is involved. Other people think relational languages actually implement relational algebra.) Received on Fri Sep 04 2009 - 23:10:56 CEST

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