Very Computer

I am a recently laid off MS SQL DBA of five years.  I would like to have to
some advice on learning Oracle.

1)How difficult is it to learn Oracle? What are the differences between MS SQL
and Oracle? I know both are ANSI-92 complaint RDBMS. What is the major
differences between SQL, SQL plus, and PL/SQL?

2)Given the fact that both DB2 and MS SQL are taking market share away from
Oracle, how does its future look like? Is the declining marketshare due to
lesser technology or dubious pricing schemes by Oracle?

3)How will someone like me benefit from learning Oracle? How will it increase
my marketability in the job market?

4)What are some of the best books to learn Oracle? What is the best way to
learn Oracle?

4)How important is Unix knowledge to a Oracle DBA?

Thank you in advance.

Jinsoo
MCSE+I, MCDBA, MCSD, CCNA

The differences are very large. Not superficially but as you get deeper and deeper
into the products. And ANSI-92 compliance isn't one thing. It is many things.
Including the ability of vendors to implement the standard by different methods
and with different syntaxes.

If you want to learn Oracle your previous experience will be valuable but you will
need to approach it with an understanding that much of what you assume is valid
may not be. For example Oracle has something basic to its model called
multiversioning that doesn't exist in any form in SQL Server. Locks are not a
limited resource. Temp tables are almost never used and certainly not built
on-the-fly in procedures.

My suggestion would be to start of with Tom Kyte's book "expert one-on-one
Oracle." Especially the first three chapters.

Daniel Morgan

Quote:> I am a recently laid off MS SQL DBA of five years.  I would like to have
to
> some advice on learning Oracle.

> 1)How difficult is it to learn Oracle? What are the differences between MS
SQL
> and Oracle? I know both are ANSI-92 complaint RDBMS. What is the major
> differences between SQL, SQL plus, and PL/SQL?

several questions.

It should be relatively straightforward to pick up Oracle if you have a good
DBMS background.

Differences. Haven't seen a list recently. architecturally Oracle makes undo
records of its changed blocks which are then used for read consistent images
for other sessions. This has a number of nice consequences particularly the
mantra "writers don't block readers, readers don't block writers". Oracle
writes to its transaction/redo logs in a circular fashion so the transaction
log cannot fill a disk - though its archived copies can! database means
different things. in the two worlds, autoextend is a bad thing. installing
using the supplied oracle defaults is a bad thing etc etc.

Quote:

> 2)Given the fact that both DB2 and MS SQL are taking market share away
from
> Oracle, how does its future look like? Is the declining marketshare due to
> lesser technology or dubious pricing schemes by Oracle?

Marketshare figures are arguable. I'd say that Oracle, DB2 and SQL will be
around for at least the next decade.

Quote:

> 3)How will someone like me benefit from learning Oracle? How will it
increase
> my marketability in the job market?

you'll learn a Man's DBMS! No seriously any survey of skills will show both
sql and oracle as highly desirable, in addition many jobs that are primarily
either sql or oracle require exposure to the other system as well.

Quote:

> 4)What are some of the best books to learn Oracle? What is the best way to
> learn Oracle?

The oracle concepts manual. (oracle docs available at tahiti.oracle.com)
The oracle dba handbook (kevin loney)
(if you are a development DBA minded person) Expert One-On-One Oracle -
Thomas Kyte
Jonathan Lewis' book Practical Oracle8i is great as well - the man can write
and is technically accurate- but may not be appropriate to a learner.

best thing to do is to download Oracle from technet.oracle.com and install
on a win2k/winxp prof machine. If you are bandwidth challenged then order a
copy from your local oracle office.

Quote:

> 4)How important is Unix knowledge to a Oracle DBA?

It depends. IN an NT environment unimportant, in a N*x environment with no
sysadmin vital. Other environments it will depend.

Quote:

> Thank you in advance.

> Jinsoo
> MCSE+I, MCDBA, MCSD, CCNA

don't bother adding OCP to that list till you have a year or so's
experience.

Quote:>What is the major
>differences between SQL, SQL plus, and PL/SQL?

SQL is the basic language for doing queries, insert / update / delete
etc. one statement at a time.

PL/SQL lets you do loops, IF-THEN, procedure calls, declare variables,
etc. with SQL statements interspersed.  You would typically use it for
the bodies of triggers and stored procedures.  There are lots of APIs
callable from PL/SQL.

SQL*Plus is a tool for interactively issuing SQL statements and PL/SQL
blocks.  Many of its commands are concerned with formatting the output
--- how wide to make each column, whether to pause after each N lines,
etc.

Each one has its own reference book, and various others explain how to
accomplish particular tasks with one language or a mixture of
languages:

http://tahiti.oracle.com/pls/db901/db901.docindex?preference=SQL

When you're typing away in SQL*Plus, it isn't so important which
command is part of which language or tool, so there is a quick
reference that combines syntax for SQL, PL/SQL, and SQL*Plus:

http://tahiti.oracle.com/pls/db901/db901.sql_keywords

John
--
Got an Oracle database question?
Try the search engine for the database docs at:
http://tahiti.oracle.com/

The opinions expressed above are mine and do not
necessarily reflect those of Oracle Corporation.

hi,

oracle is old fashioned crap.

stick to ms-sql server , it will overtake the market

everybody is porting oracle to db2 and ms-sql

oracle will lay off very soon

everybody is going windows and sql-server !!!!

Quote:> I am a recently laid off MS SQL DBA of five years.  I would like to have
to
> some advice on learning Oracle.

> 1)How difficult is it to learn Oracle? What are the differences between MS
SQL
> and Oracle? I know both are ANSI-92 complaint RDBMS. What is the major
> differences between SQL, SQL plus, and PL/SQL?

> 2)Given the fact that both DB2 and MS SQL are taking market share away
from
> Oracle, how does its future look like? Is the declining marketshare due to
> lesser technology or dubious pricing schemes by Oracle?

> 3)How will someone like me benefit from learning Oracle? How will it
increase
> my marketability in the job market?

> 4)What are some of the best books to learn Oracle? What is the best way to
> learn Oracle?

> 4)How important is Unix knowledge to a Oracle DBA?

> Thank you in advance.

> Jinsoo
> MCSE+I, MCDBA, MCSD, CCNA

don't event try to find a job as oracle-dba in this economy !!!

db2 is better than oracle, go for db2 and ms-sql

now db2 is nr 1 , but ms will overtake this market very soon

ms-sql-net-enterprise is the monster , it will  benchmark oracle into the
ground with the new cluster-technologie !!!

Quote:> I am a recently laid off MS SQL DBA of five years.  I would like to have
to
> some advice on learning Oracle.

> 1)How difficult is it to learn Oracle? What are the differences between MS
SQL
> and Oracle? I know both are ANSI-92 complaint RDBMS. What is the major
> differences between SQL, SQL plus, and PL/SQL?

> 2)Given the fact that both DB2 and MS SQL are taking market share away
from
> Oracle, how does its future look like? Is the declining marketshare due to
> lesser technology or dubious pricing schemes by Oracle?

> 3)How will someone like me benefit from learning Oracle? How will it
increase
> my marketability in the job market?

> 4)What are some of the best books to learn Oracle? What is the best way to
> learn Oracle?

> 4)How important is Unix knowledge to a Oracle DBA?

> Thank you in advance.

> Jinsoo
> MCSE+I, MCDBA, MCSD, CCNA

Likely that explains why there are currently 52 Oracle jobs in the Puget Sound
area of Washington State (in short Seattle, Bellevue, and Redmond WA) and 55 SQL
Server jobs. And why the Oracle jobs pay more (source http://www.dice.com
11-MAY-2002). Likely also explains why for the past four years almost all of my
consulting engagements have involved companies moving their software from SQL
Server to Oracle. Last year a decision made by a little company that knows
nothing about technology named AT&T Wireless.

Thanks again for the laugh.

Daniel Morgan

Quote:

> everybody is going windows and sql-server !!!!

Says he of the multiple posts and personalities from the same host:

and

Man!  I love newsreaders with a little bit more functionality than the
usual M$ crap.  One can pick up these ones so fast it's not even funny.
:D

--
Cheers
Nuno Souto

Daniel,

You have made some excellent posts on here. However, suggesting Tom
Kytes book to someone just learning Oracle is a really bad idea. He
assumes you know quite a bit in writing it. I really think you should
start with the basics and start with the developer side of it. PL/SQL
and Forms. Since you wont get a DBA job for 2-3 years anyway.

1. You dont really start off learning 'Oracle' per say. You start off
learning the development programming side. Focus on SQL and PL/SQL.
SQL*Plus is a client program that allows you to access the database.
Has some decent scripting stuff, but it is NOT important right away
and you can just grab what you need out of a book anyway.

SQL is for manipulating the data and for making changes to the
database.
PL/SQL is close to a full blown programming language. You can use SQL
with in it.

Focus on these two and learning the Oracle Forms tool as well. Its a
tool that allows you to make screens for users to access the database.

Quote:

> 2)Given the fact that both DB2 and MS SQL are taking market share away from
> Oracle, how does its future look like? Is the declining marketshare due to
> lesser technology or dubious pricing schemes by Oracle?

I hear this alot. However, SQL Server jobs dont pay real well and its
lower end. You dont see the DOD run high end servers on SQL Server. I
dont see many DB2 jobs advertised at all.

Quote:

> 3)How will someone like me benefit from learning Oracle? How will it increase
> my marketability in the job market?

You have IT experience which is VERY good. However, you must start as
a developer and NOT as a DBA. There are no entry level DBA jobs. You
have to be more of a programmer first for 2-3 years then you may be
able to move over. Anyone who says you can start as a DBA is either
lying or an idiot. Now this is a DBA forum, but its not like
developers are on welfare....

Quote:

> 4)What are some of the best books to learn Oracle? What is the best way to
> learn Oracle?

There really arent any good ones unfortunately. Tom Kytes book is
recommended, but save your money. Its only good after you have been
working in the business for 6-12 months. Long time DBAs sometimes
forget what it takes to learn a brand new skillset.

Look for SQL and PL/SQL books that have actual exercises. I like the
Oracle SQL Interactive Workbook and the Oracle PL/SQL interactive
workbook. They have a database you can download that they teach from
and have assignments. Very important.

You can get the Oracle database off of otn.oracle.com for free.
However, you need Windows 2k to run it and they recommend 512 MB of
RAM(I think... cant remember).. still running 8i at home.

Quote:

> 4)How important is Unix knowledge to a Oracle DBA?

Most of the really high end databases are run on some form of Unix.
Very useful. However, since you will start as a developer, you really
only need to know how to get around in it. Then pick up a little more
at a time. There are ALOT of development projects run on Windows
though, especially OLTPs. Many high budget ones too, but Unix is
invaluable to a DBA.

You will not be a DBA right away. You HAVE to start as a developer.
Which means do not start by learning about the architecture, or about
performance tuning, or about how the database actually works. Gonna
get flamed for that one... those are a bit more advanced.

Start with SQL,PL/SQL and Forms. Oh yeah you can download forms for
free too. Its part of the 'Internet Application Developer Suite' or
something like that. New one just came out so its probably gonna be
real buggy for 6 months and I dont think you can get the old one
anymore.

Quote:

> Thank you in advance.

> Jinsoo
> MCSE+I, MCDBA, MCSD, CCNA

Funny thing is that I've started as DBA and learned SQL programming
later (and I still do not know Oracle Forms :->). I do not think that
this is a usual aproach, but saying something like: "you must start as
a developer and NOT as a DBA" is too much generic.

Quote:> You can get the Oracle database off of otn.oracle.com for free.
> However, you need Windows 2k to run it and they recommend 512 MB of
> RAM(I think... cant remember).. still running 8i at home.

Oracle 9i works on 256MB RAM with no problem (and no performance, but
on toy database it is not an issue).

Quote:> Most of the really high end databases are run on some form of Unix.
> Very useful. However, since you will start as a developer, you really
> only need to know how to get around in it.

Is good to know Unix even for developer. We've had (and still have) a
lot of problems with database application in Unix environment because
of developers had no clue about Unix.

Quote:> You will not be a DBA right away. You HAVE to start as a developer.
> Which means do not start by learning about the architecture, or about
> performance tuning, or about how the database actually works. Gonna
> get flamed for that one... those are a bit more advanced.

Yes, I'm going to flame you right now !!! ;-)
For all developers: Please read Oracle Concepts. You should know
something about architecture of database you're writing for. I'm tired
about all that worthless talks about purpose of schemas, why database
!= schema, why more than one schemas can be in one tablespace, why is
not a good idea to put two 30gig database in one instance even if
they're on the same DB server etc ...
And performance tuning is indeed the must for any Oracle developer.
New developer should start with learning about performance impacts of
various SQLs as soon as wrote the first lines of code. Oracle
developer without tuning skills is worthless and even dangerous.

--
_________________________________________

Dusan Bolek, Ing.
Oracle team leader

can call it an overture to bankruptcy) on that server. I'm still using
this email to prevent SPAM. Maybe one day I will change it and have a
proper mail even for news, but right now I can be reached by this
email.

Dusan,
Right on.  Yes, the developer should have at least a basic understanding of
how the backend works.  Just the other day I had a developer want to create
temp tables because that's what you do in Sybase.  I spent some time
explaining Oracle to them and they were pleased as punch that they didn't
have to deal with that mess anymore.  What also surprises me is those
developers that don't read the APPLICATION developers guide. So they don't
put performance in from the start - "we will tune later."  Performance is
part of the daily job not something you bolt on later.  Okay, I occasionally
use the _run_faster=true parameter, but usually I make the developers fix
it. :-)

Jim

Well, well, I have a DBA running around saying '*don't use* nvl and decode.

Can you imagine why ? (comment was: don't use them in a where clause and
by the way what's a function (further on - what's the difference between a
function
and a procedure - no, I'm not joking !))

I do somewhat agree with your comments below Jim,  but I disagree that they
only
apply to developers.

When has it ever been possible to include sufficient time
to 'put performance in from the start'  ?
(the answer I always get is 'cut your estimate by x%')

Keld.

When did you start out as a DBA without being a developer and how many
jobs do you know that are open for DBA's who were not developers
first? Almost none....
So if you tell people to try to be DBAs first nearly all of them will
not get a job.

Yes, developers should learn the database, its not a pre-requisite to
get your first job. In your first job they will want you to know some
SQL, PL/SQL and probably forms and/or reports. You really think the
DBA is gonna let some entry level DBA have anything to do with
performance?

The concepts document is excellent to read after you have 6 months
working experience. It covers too many topics before that. Even then,
Id recommend 3 reads over a period of 2-3 months to digest it all.

Well, I didn't mean to limit it to developers.  DBA';s should read the
application developers guides also.  It would be nice if managers had a
clue, but often they don't.  By performance I mean that if you know x is
better than y then do x not y unless there is a really good reason not to do
x. (eg "We'll put in bind variables later, when we get to the performance
phase of the project." or "We will fix that problem where we read from the
same table 120 times during a calculation when we get to the performance
phase of the project."  These are real comments.)  Sure if you don't know
then I can understand, but if you know you should do something basic in
advance then do it don't put it off!

Jim