I am pretty naive when it comes to DB theory but there is something I
am trying to find out and having no luck. In Codd's 70's paper on the
relational database, he explains normalization as a process of taking
non-simple domains out and create separate relations where the primary

Generally speaking, we seem to use the word hierarchy to mean a situation
where a table has a foreign key to itself (or a child table has two foreign
keys to the same table that are non-transitive), with the usual assumption
that nesting could go to any level and that the levels are

Given two tables that are not UNION compatible, it seems there are ways to
UNION them anyway.
Method 1, Intersect their headers.  The resulting header is used to project
both tables and now those projections are union compatible.  What would

Hey Fran, This one's for you.
Over the course of time,  I've looked for web resources that illustrate
database design principles, so that I can refer to them instead of typing in
the same responses over and over again.

I'm teaching in computing. A question appeared in a trial paper
recently and I'm trying to establish whether the suggested answer is
correct.
The question was:

Here are two missing elements: 11, and relation complement ^A.
Axioms:
A join ^A = 00 join A
A union ^A = 11 union A

Please let me know if there is any way to make to this possible.
And another issue we are facing is that, SQL 2000 is consuming a lot of
memory and not releasing it. Is there wany to make this SQL 2000 to
release the memory when it does not require.

There is a new book on indexing SQL-DBMS'es
by Tapio Lahdenmaki and Michael Leach.
Relational Database Index Design and the Optimizers
See

Can someone explain to be me the difference to between an identifying
relation and a non-identifying relation?  I came across these terms when
I recently started looking into using ERM tool.
TIA,

A month or so ago we were discussing relational algebras, and
we were looking at a lattice algebra defined in a paper by
Vadim Tropashko. It had two operators, natural join and inner
union.

A few days ago,  VC commented on my use of the word "symbol" saying that I
was inventing new terminology.  I'm trying to restrain the urge to rant,
and just give a sober reply.
There is a book on my shelves, thanks to Joe Celko,  who mailed it to me for

I'm sure there are numerous factors playing into the fact that the
system touted in this MS Word document
http://www.microsoft.com/resources/casestudies/ShowFile.asp?FileResourceID=1611
has been discontinued and written off to the tune of $67 million in s/w

There's been discussion about whether the relational engine does or does not
understand equality.  I'd like to suggest that the relational engine does
understand the "what" of equality testing,  but is sometimes naive about the
"how".  Before I go any further with this,  let me ...

I need to produce a macro for a project that I have to do in my course in IT
"Certificate III IT (Software Applications) Unit ICAITUO18C". The macro
needs to validate previously imported data from Text Files. I have already
written the macro to import the data and now this ...

If semiotics is all about writers like Humberto Eco,  then it's a little far
afield even for my tastes.
Now, if Eco had written about say, how we name data,  I might have read him
a little more.