How difficult is it to learn Oracle if you already know SQl server?

Oracle has its own flavour of the SQL language, which is noticeably different from T-SQL. If you are serious about learning it then unfortunately, you will have to forget about the Oracle's Enterprise Manager or Oracle's PL_SQL+ editor and opt to use a third-party tool, such as Embarcadero's DBArtizan or Quest Software Toad.

One small example of the drastic difference between Oracle' SQL and T-SQL:

In SQL Server, you can easily create a stored procedure which selects some data, such as

create proc dbo.SomeProcName as
begin;
    set nocount on;
    select some_columns from some_join_of_some_tables;
    set nocount off;
end;
go

Well, in Oracle, the usage of the reserved word SELECT is prohibited from being used in the stored procedure UNLESS it is a part of some sort of SELECT INTO statement. In other words, you will have to declare so-called reference cursor, select your data into it and then return it. On the top of all this, you will have to create a package which will consist of the package head and package body, which in turn will include the text of your stored procedure. Then you can deploy the package so the procedure can be finally used.

The above example is just to demonstrate that generally speaking, everything in Oracle is more complex than it needs to be, and while their database engine is admittedly powerful, development and maintanence of an Oracle database is a nightmare when compared with SQL Server. In my humble opinion, the true reasons why many people still use Oracle are:

• Advanced age of the decision makers
• Their stubborness and unwillingness to admit the reality.

I had to work with Oracle databases for a number of years, and was lucky enough to earn respect of the Oracle DB Administrators, but I am really glad that I don't have to do it any more.

In the past, a decent resource to ask Oracle related question was Ask Tom, but I am not sure whether it is still active or not. In any case, it is far easier to find very good resources to learn SQL Server than Oracle.

Just my 2 cents.

Oleg

I have a handy reference book, "SQL In A Nutshell", which covers MySQL, Oracle, PostgreSQL and SQL Server. It's also available on Safari Books Online. It goes through the basic T-SQL keywords and describes the differences in implementation between versions.

Of course, me being me, I'm now going to whinge that it doesn't cover Informix - if it had, I would have bought it years ago!

Additional, as this discussion seems to have resurrected itself...

There is a presentation on the SQLBits website a from a SQLBits conference where Gavin Payne provides an introduction to Oracle for the SQL Server DBA. Might be worth checking it out.

A big consideration is how comfortable or familiar you are with the underlying O/S that Oracle is running on. As it is a third-party app it doesn't have the same relationships as SQL Server does with Windows for instance. To really manage it you need to understand command-line management of file systems at a minimum.

Getting into it is rather easy... mastering it takes years. Some things are straightforward and make a lot of sense from a SQL Server perspective, others will have you very confused until you re-learn under the Oracle model.

If you don't do a lot of hand coded queries to manage SQL Server currently you may find Oracle very daunting.

ANSI standards are just that. If you know T-SQL standards it shouldn't take to terribly long to come up to speed regardless moving from SQL to Oracle or Oracle to SQL. Learning the different tool sets is what will take the longest. MSSQL has a lot of GUI's to assist with basic tasks. That is not so much the case with Oracle. Lots of third party tools help with that with Oracle.

I installed Oracle Database Express Edition.

I uninstalled Oracle Database Express Edition 2 days later.