Oracle Migration Workbench - Part Four
By Steve Callan
At the end of Part Three, we finished installing SQL Server and created a
user account that has access to the Northwind database. In Part
Four, we will go into more detail about SQL Server and how it
compares to Oracle. This part of the series also covers the setup
and preparation to use Oracle Migration Workbench to migrate the
Northwind database from SQL Server to Oracle.
SQL Server versus Oracle
To be more precise, that is SQL Server 2000
versus Oracle9i. By and large, I believe the supporters of each
product are firmly encamped, that is, they believe theirs is THE
database product and all others pale in comparison. In a segmented
market where product share is widely distributed by platform and
type of user, there is no reason to fault anyone for his or her
belief about which product is the best, because "best" for one
person may not be "best" for the other. There is an historical
analogy, which parallels the RDBMS "mine is the best" mindset, and
it has to do with word processing.
If you were on computers in the late
1980's/early 1990's, you may recall the word processing war among
WordStar, WordPerfect, MultiMate, DisplayWrite and the emerging
Microsoft product called Word. Lotus had something too as I
recall. Whichever product you started with, you tended to stay
with it. My favorite was a product named ProWrite, and it was
definitely Off-Broadway in terms of being an actor. Who rules
today? Microsoft Word has become, for all practical purposes, the
lingua franca of the word processing
world. One of the top hits on a Google search for MultiMate is
about a cow mating program. Ouch. Not to mention all those brain
cells I stressed trying to remember the 40-plus MultiMate
Ctrl-Alt-Shift F-whatever keystroke combinations to make a
document look halfway decent - who would put up with a program
like that in today's world of software?
Part of the purpose of this series, as far as
Oracle DBAs are concerned, is to provide some background for you
about other RDBMS products (MySQL and SQL Server as mentioned, and
this may extend to DB2). For open source, inexpensive database
needs for a small web site, MySQL certainly fills the bill. As a
small-to-medium business, the answer is a bit murky as to which
product suits your need. Pricing, performance, ease of use, and
reliability are critical considerations is selecting a product.
If you are coming from the Oracle world and you
take the time and effort to get into some of the features of SQL
Server, you are going to walk away with both of these impressions:
1) "Wow, I wish Oracle did that."
2) "Gee, I hope Oracle does that in its next
SQL Server's interface and easily accessible
functionality, presented either via GUI-based menus or supplied by
ready-to-use scripts and procedures, is far superior to what
Oracle offers out of the box, and that superiority extends to
something you only get once: a chance to make a first impression.
The appearance of SQL Server tools, by the very nature of its one
and only platform, capitalizes on the Windows look and feel.
Oracle, on the other hand, uses Java-based GUI interfaces, which,
without getting into Java's limitations on GUI, just does not have
the same pizzazz as a true Windows-based interface. Then again,
you will not see SQL Server on a UNIX-based platform. The "Which
is the better server platform, Windows or UNIX?" debate is for
someone else to moderate.
If you have a firm grasp of Oracle's
architecture, learning SQL Server's setup is a relative breeze.
You know what has to be done or what should take place in Oracle,
so your task is to learn how SQL Server accomplishes the same
things. However, there are several key differences in the "how"
A quick overview of the differences at this
point will be helpful. There are plenty of other sources which
cover these differences. A Prentice Hall book titled "Microsoft
SQL Server 2000 Database Administrator's Guide" is one such
reference. It includes a chapter about migrating from Oracle to
SQL Server, and you can see how Microsoft's approach to what makes
a database work is similar and different from Oracle's approach.
The documentation which comes with Migration Workbench includes a
side-by-side comparison of these database systems. SQL Server,
like Oracle, runs on ACID. That's "ACID" as in Atomic, Consistent,
Isolated, and Durable. If a database system can't pass the acid
test, so to speak, you cannot be certain about the accuracy and
consistency of its data, and without that, what good is it?