A little background: I've done a fair bit of database application
programming over the years, starting with MS Access 2 and 97 <shudder> and
have read a lot about database theory, starting with this book:
http://www.amazon ...

I found this that explains why I was using "Logical Data Model" the way
I did in my previous question.  I gather from the responses that many,
but not all, disagree with this use of the term.  So, it can be a
starting point -- let me know what should be corrected for a more

I've been misspelling your name.  I've been writing it as "Roy Hamm".  Just
a simple error,  no hidden message.
The reason I want to get your name right is that I want to attribute to you
one of the great sayings of all time in information science.  The phrase is

There's a very nice browser that is called Smart Bro. I think this
browser is the best browser in the market. It has:
1. Very nice and clean interface.
2. Tabbed browsing.

This is a real pickle. My company's web application offers a lot of
ways to order products, so there are quite a few Order/OrderDetail
tables in the db (one for every type of order).
The problem is that the Order Detail tables aren't denormalized,

There are various different approaches one can take for embedding
a domain specific lanuage into a general purpose programming language.
Common examples are regular expression libraries inside languages
that don't directly support regular expressions, and, directly to our

I have two tables:
purchase  (ItemId, PurchQuantity, PurchaseDate);
sales     (ItemId, SalesQuantity, SalesDate);
With these two table could I able to find:

Is the following a true and accurate statement within the context of a
physical schema?
"a foreign key constraint defines a relationship to another table"
Thanks,

  I am preparing an analysis report and need some help.
  Currently, what is the most efficient / most used way of ensuring
global concurrency control / serializability in federated
databases/multidatabases ??

Haven't seen the topic, so here goes.
What adverse impact can be seen to the future of the Relational/SQL
database from the implications of multi-core chips and the resulting
parallelism?

Hi to all
I've a question about 5NF. For the sake of brevity, let's take the
explanation and the example present on Wikipedia:
http://en.wikipedia.org/wiki/5NF

Given two tables A and B, both containing a column X with identical
data, I'm trying to formulate a query which will return all rows from
table A where there are no rows in table B with a matching value in
column X.

This question is a easy one.
Given:

pR = tuples/page

Here is a question that I came up while reading up on b+ trees. For
some reason I am having a problem understanding some of the terms and
the mechanical part of the tree.
So from what I understand, b+ tree is a representation of the index

I am a newcomer in the field (must be obvious from the question), and
have one basic doubt.
Since data streams are continuous and one time, and DBMS is for storing
, managing and retrieving persistent and discrete data, why do we need