At the moment alternatives like APEX are not widely used in the E-Business area. Maybe due to the following reasons:

• E-Business  customers are not yet aware of the possibilities of APEX within E-Business;
• E-Business customers are not yet aware of the lower costs of APEX development in e-business;
• E-Business  customers are not yet aware that the tool is free as it comes pre-installed with Oracle XE and 11g;
• APEX consultancy companies do not have the E-Business knowledge.

Since the very beginning we, at iAdvise, believed in the possibilities of APEX as a valid “alternative” platform for building cost-effective, open, reliable E-Business customizations and extensions.
We think of different use-cases where APEX can be used for custom development:

• Custom data collection, for which today Excel is often used
• Building New applications, in support of business processes not covered by standard APPS
• Reporting and data analysis, when necessary with real time access to EBS data
• Modernization of custom Oracle Forms applications

Already in 2008 we did a modernization exercise for existing APPs functionality. The customer wanted a more efficient way for manually introducing invoices in the system. We developed a small Quick Entry application, in APEX 3.0. Via a small wizard,  the user can enter the necessary data. Following screenshot shows Step 2 of the wizard where one or more order lines could be defined.

Quick Entry AR Invoices: Step 2

When pressing Finish at the last step, the newly created invoice is added in the APPs tables via the standard APIs. We have also foreseen the possibility to switch to the ‘Open Interface (OI)’ mode: instead of using the APIs, the data is in inserted in the available Open Interface tables.

Since last year, Oracle also officially declared APEX as a valid tool to extend Oracle APPs by publishing the already famous white paper that gives a very good explanation how you can integrate both environments.

In the BeNeLux the interest is growing for this combination. Therefor we are happy with the OBUG initiative to organize on the 15th of February an APEX-EBS combi-SIG. You can subscribe for this event via the OBUG site.

We will be there !

The most recent is about heterogeneous services (also referenced as HS). Here is the case:
We have an Oracle DB instance with some APEX applications and in one of those applications I need data from a MS SQL server database. Not a very good idea, but the set-up couldn’t be changed and both databases can handle it, so I gave it a try.

Our DBA installed heterogeneous services and created a database link between the two databases. Querying the necessary views was pretty easy (I only needed a couple of synonyms for ease of maintenance) and data came in faster than expected.

The next step was to query these views with APEX.
Because I created Oracle views on the views of MS SQL server, this was also very straightforward for APEX.

After a while however, there were issues in other applications and also the APEX builder itself raised errors while uploading files and importing applications. The following error returned:

ORA-02047: cannot join the distributed transaction in progress

, usually accompanied by some other ORA error codes. Not a very descriptive error message. A colleague pointed out to me that it has something to do with database links and heterogeneous services.

So, what is the problem?
APEX starts a new database session for my application. In this session the database link to the MS SQL server database is opened and data is queried. Since APEX constantly changes and re‑uses database sessions (this technique is called session pooling), the database session is released after a while and put back in the session pool until another application needs a new/another session. Because the database link in my session is only used for querying, there is no line of code that closes the database link so it remains open, even when the session is put back into the session pool. When another application takes this session from the pool, there might be issues with specific transactions, like setting a context (e.g. setting NLS parameters), because Oracle wants to perform this operation on both the Oracle database and the linked MS SQL server database. Because an NLS parameter is set when uploading a file, the end user receives the ORA-02047 error.

What can one do to prevent this from happening? There are several solutions for this issue:

1. Don’t use database links with heterogeneous services. This is the easiest solution but isn’t always possible.
2. Only access data over a DB link with HS in a package, function, procedure,… and close the DB link at the end of your block of code, which is not always possible either.
3. Close any open database link, or only the specific one, when you put your session back into the session pool.

For the third solution, something interesting is implemented in APEX 4.1.

At application level, you can define some PL/SQL code that should be executed when initializing or returning a session from/to the session pool.

You can find this section under Shared Components  >  Security Attributes. All the way at the bottom is the section ‘Database Session’:

In earlier versions of APEX, something similar was already available for VPD (Virtual Private Database) but this only allowed execution of code at session initialization. The APEX development team has now expanded this functionality for any PL/SQL in general, so not only VPD-related, and both at session initialization and returning.

For my issue, all I had to do was write some code to close the database link when it was still open. I created a function in my application database schema which returns the number of open database links with a specified name:

CREATE FUNCTION is_dblink_open(dblink  IN VARCHAR2)
RETURN INT
AS
  l_cnt   INT;
BEGIN
  SELECT COUNT(db_link) INTO l_cnt
  FROM v$dblink
  WHERE db_link = dblink;

  RETURN l_cnt;

EXCEPTION
  WHEN NO_DATA_FOUND THEN
    RETURN 0;
END;

Before you create this function, don’t forget to grant access to v$dblink:

GRANT select ON v_$dblink TO my_app_schema;

Execute with SYS. Note the v_$ instead of v$! (more info: http://goo.gl/euxcs).

All that was left is to use this function in the Database Session Clean Up Code:

DECLARE
  l_dblink VARCHAR2(100) := 'MY_SQL_SRV_DBLINK';
BEGIN
  IF is_dblink_open(l_dblink) > 0 THEN
    DBMS_SESSION.close_database_link(l_dblink);
  END IF;
END;

Or if you want to be sure that all open database links are closed, you could use:

BEGIN
  FOR l_db_link IN ( SELECT db_link AS name FROM v$dblink ) LOOP
    DBMS_SESSION.close_database_link(l_db_link.name);
  END LOOP;
END;

Special thanks to my colleague Jan for pointing out to the HS problem and to Patrick Wolf for helping me on this issue through the Oracle APEX forum (read the full post here: http://goo.gl/vVoeb).

This way, I hope to help out other people too when they run into this issue.

But to keep the story short, she asked colleagues to contribute and asked me if I could write something about PL/SQL.
Sure I wanted to do that!  But about what in PL/SQL?  There so much to talk about…
I got “carte blanch”, so I started looking for topics: hints and tips, must know features, technical solutions,…
What else comes up when thinking about PL/SQL?
Indeed…Steven Feuerstein.

Wouldn’t it be cool to start with an interview with Steven Feuerstein?
I contacted Steven and he was prepared to answer some questions for “De Poreiflash”.
The first issue of “De Poreiflash” appeared two weeks ago.  An did a great job with our company magazine, it looks fantastic!
And here’s the interview how it appeared in “De Poreiflash”.
Somethings are already outdated: in the meantime Steven became a grandfather!
Congratulations Steven!

Q. Steven Feuerstein, the person with a PL/SQL obsession.  Introduction is probably not needed for people working with Oracle. Maybe a short one?

Sure. Well, yes, I think I do qualify as having an obsession about PL/SQL. I’ve written 10 books on the language and have spent most of my professional life since 1994 reading about, writing about, writing and generally wrestling with PL/SQL. Along the way, I’ve gathered some awards and related projects: I’ve been developing software since 1980, spent five years with Oracle (1987-1992), and have served as PL/SQL Evangelist for Quest Software since January 2001.

I am an Oracle ACE Director and write regularly for Oracle Magazine, which named me the PL/SQL Developer of the Year in both 2002 and 2006. I am also the first recipient of ODTUG’s Lifetime Achievement Award (2009).

In 2010, I started the PL/SQL Challenge, an online, daily PL/SQL quiz (now also offering weekly APEX, SQL and logic quizzes). In 2011, I launched PL/SQL Channel, a library of over 27 hours of detailed training on Oracle PL/SQL.

Q. How did you enter the Oracle world and got obsessed with PL/SQL?

I “fell” into the world of Oracle entirely by chance. I came out of university a Fortran programmer and ended up at Abbott Laboratories as a consultant, during which time I was introduced to databases on DEC10s and DEC20s. From there, I moved to CNA (insurance) in downtown Chicago and that was an incredibly boring job, though I did spend more time with a non-relational database while there.

So, bored out of my mind, with a newborn baby eating me out of house and home, I decided to look for a new position, and came across a Help Wanted ad looking for a person with relational database experience. Well, one of those words was familiar! So I got hold of an article on relational databases (Codd’s 12 rules), memorized that, and went to the interview. Turned out to be for a pre-sales job with Oracle. They were more interested in my ability to speak to large groups than my technical background. In any case, I was hired – the main issue for me was deciding whether or not I wanted to take a job that required wearing a suit and tie every day.

I spent a couple of years following salespeople around to accounts and doing the dog-and-pony shows for them with SQL*Plus, SQL*Forms, etc. Presales was interesting and sometimes exciting, but programming was way better, so I would constantly dabble with the Oracle tools, building little apps for my co-workers to use. This developed into TeamSell, a sales support application that caught the eye of Mike Fields, head of U.S. Sales in the early ’90s. I was drafted to join a small dev team and we started building some very cool SQL*Forms apps to support the U.S. sales force.

Then Larry canned Mike, and I was told to go back out on the road to help sell Oracle. I said no thanks, and took the first consulting job I was offered. Two years later, I saw an appeal on CompuServe for Oracle authors and I thought “Why not? I can write.” So I wrote Oracle PL/SQL Programming, which was the first independent text on PL/SQL, and it changed my life. From that point on, I was virtually a full-time student of the PL/SQL language, researching, writing, teaching, building code, etc. As I mentioned earlier, once you can structure your own time, all it takes is discipline­and reasonably good typing skills­and you can accomplish an awful lot!

I can still remember thinking as I signed the contract with O’Reilly that stipulated a book of 400 pages: “Is there really that much to write about PL/SQL?” 1200 pages later, we had to cut 400 pages to publish the first edition. Those 400 pages were all about writing PL/SQL in Oracle Forms and Reports. We should have published that immediately as a “side book.” Ah well….

Q. What’s your current job?

I am the PL/SQL Evangelist for Quest Software, have been since 2001. What this means, for the most part, is that Quest gives me lots of freedom to continue to explore the language, and support the worldwide PL/SQL community. Of course, I also do some product development, design and marketing. But I do think that Quest deserves lots of credit and a big thank you from PL/SQL developers around the world for making it possible for me to maintain my expertise and help other developers around the world.

Q. Other activities?

Ah, well, I used to play racquetball, go on lots of long bicycle rides, all sorts of things. Now, as I move through my sixth decade on Planet Earth, I find myself spending more time than ever in front of my laptop (believe me, it is not easy to write five new PL/SQL quizzes each week!) and THAT IS NOT A GOOD THING. So I struggle to keep my body in decent shop and avoid the problems associated with lots of typing and lots of staring at screens. But soon I will have a major new activity: I will be a grandfather by early November. Very exciting!

Q. About the PL/SQL Challenge…  What is it?

The PL/SQL Challenge is my latest and greatest effort to (a) coalesce an active, engaged, global community of PL/SQL developers, and (b) “download” my PL/SQL expertise from my brain into a format that is accessible to all developers and will be around long after I am gone. There are lots of sites that offer Q&A for PL/SQL and SQL; I am not interested in providing another of those. Instead, I think that developers are like “normal” human beings: we like to compete, we like to win prizes, we like to be recognized, we like to be challenged.

The PL/SQL Challenge does all of that: you take daily, weekly and monthly quizzes, competing with hundreds (and hopefully soon thousands) of other Oracle technologists. Of course, you don’t have to “compete”. You can simply take the quizzes (using, by the way, a nickname that does not reveal your true identity) as another way to deepen your knowledge of PL/SQL and related technologies like SQL and APEX.

So today it is a totally free quiz-driven learning experience. Soon, we will make it possible for you to join the PL/SQL Challenge by paying a small annual membership fee. Members will be able to utilize special features such as Practice Makes Expert, in which you can take past quizzes as often as you like, thereby sharpening your command of the PL/SQL language, and Quizbook, which will allow you to export quizzes as PDF “books” that you can use when away from the website – or to present to your manager to show her how much effort you are making to improve your technical skills.

If you haven’t registered and tried out the PL/SQL Challenge, I strongly encourage you to do so!

Q. Why should one participate?

Why not? It just takes a few minutes a day, and you are sure to either learn something new or demonstrate to everyone that you are well-versed in that particular feature of PL/SQL. When you play, you have the chance to win some prizes (ranging from O’Reilly ebooks to $250 Amazon.com gift cards).

Q. Some tips about developing PL/SQL?  Eg. on performance or hardcoding.

If you are not thoroughly comfortable with and applying everything on the list below, then you have a clear set of next steps when it comes to your PL/SQL training:

• Collections
• BULK COLLECT and FORALL
• Autonomous transactions
• Function result cache
• DBMS_UTILITY.FORMAT_ERROR_BACKTRACE
• DBMS_UTILITY.FORMAT_ERROR_STACK
• DBMS_UTILITY.FORMAT_CALL_STACK
• Table functions
• NOCOPY

Q. Can you recommend books, websites, presentations,… about PL/SQL?

There are lots of excellent Q&A forums for PL/SQL, with the OTN forum being about the best. Stackoverflow.com also attracts lots of PL/SQL-related questions.
Another great site for PL/SQL developers is oracle-developer.net, provided by Adrian Billington.
Tim Hall’s ORACLE-BASE.com is also an excellent all-around resource for Oracle technologists.
I do encourage your readers to check out all the sites and resources I’ve been putting together in recent years:

• PLSQLChallenge.com – play and learn!
• PLSQLChannel.com – watch and learn!
• ToadWorld.com/SF – the PL/SQL Obsession site. Lots of resources to download and leverage
• StevenFeuerstein.com – sign up for my monthly PL/SQL newsletter
• ILovePLSQLand.net – vote on proposed enhancements to the PL/SQL language

Q. With your books and presentations you inspired a lot of PL/SQL developers. How does that feel?

It feels great! I expect that many companies have indirectly benefited from my writings. But what I find most rewarding is the impact I have had on the lives of individual programmers. It is not terribly uncommon to have a person walk up to me at a conference or training and offer up a variation on this story, told to me back in 1998: “I was a union electrician at a steel mill in northern Indiana. When I got laid off, I went back to school and studied Oracle programming. I got hold of your book and it changed my life. Now I have a great job, my wife doesn’t have to work and can raise our kids.” Ah, that is so satisfying!

Now, just to make sure there is no misunderstanding: I am not saying that I think everyone should follow a lifestyle in which the man works and the wife stays home with the kids.

But to have a  developer tell me his or her life was changed by my writing? Wow, what could be better? So, dear readers, don’t ever hesitate to send me an email (mailto: steven@stevenfeuerstein.com) or tell me in person about the impact my work has had on your life. I can’t get enough of that!

Q. A last message to our readers?

I just turned 53 years old. I’ve been writing software rather intensively since 1980. Thirty years of programming, thirty years of (largely) sitting in front of keyboards and screens.

It’s been a great life (and I expect lots more good years to come), but I feel more and more of late that I haven’t maintained enough of a balance. There’s a very big world out there beyond my laptop, and I should be experiencing more of it.

So that will be my last message for your readers: Enjoy writing your software, but don’t let it consume your life!

Well, here it is!

The new version can be downloaded from Oracle Technology Network.
The installation footprint is reduced, it can be integrated in Oracle Access Manager and some other new features.

* Update

Client support:

• Browser support is no longer based on Operating Systems but strictly tied to the browser themselves, no matter which Operating Systems they are installed on.
• Oracle Forms is supported on both 32 bit browsers with 32 bit Oracle JRE & 64 bit browsers with 64 bit Oracle JRE combinations.

System support:

• Oracle Weblogic Server: WLS 10.3.5
• Databases: Oracle 10.2.0.4+, Oracle 11.1.0.7+, Oracle 11.2.0.1+
• 32 bit and 64 bit systems

More about certifications.

In case you couldn’t attend the session or just want to know more about those options, you can read the following article on All Things Oracle: “What’s Your Choice for Oracle Forms?”

And now for really the first announcement…
Larry Ellison: “Everybody has a cloud, we too need a cloud”
So here it is Oracle Public Could.
Great to see Apex is strongly supported.

You can move your application and data from your datacenter to the cloud and back without a problem.
The Oracle Cloud is based on industry standards(Java, XML, Web services,…).
Pricing is based on monthly subscription, and that’s all, no extra licenses.

A second announcement: Oracle Social Network.
Collaborate, share, application integration, BI Navigation, …
He even gave a live demo of the Oracle Social Network.

Grant Ronald came on stage to explain that Oracle still doesn’t de-support Oracle Forms.
In fact, he made an announcement: Oracle Forms 11gR2 is released very soon.
The installation would be easier, integration with Oracle Access Manager, linenumbers in the PL/SQL editor and some more new features.

A lot of questions after the session and good critics.
So I’m pretty happy.

So, what’s on for today…
Wake up, breakfast, presentation rehearsal and off to Moscone to register.

And we kick of with ADF EMG sunday.

This should be interesting when you take a look at that list of speakers.

And of course later on today the keynote by Larry Ellison.
Very curious about that!

Like I said before, tomorrow is my own presentation:

• Session: What’s Your Choice for Oracle Forms: Modernize, Upgrade, Integrate, or Migrate? (session id 08262)
• Time and place: Monday, 12:30 PM, Marriott Marquis – Golden Gate A

This will be an interesting session for all Forms developers and users!

In case you’re not attending Oracle Open World, follow this blog and the iadvise twitter for regular updates from OOW.

If you want a complete overview from people attending Oracle Open World, come to the OpenXperience day on 21 October in Diegem, Belgium.
Visitors of Oracle Open World will bring you the most interesting information and hot news.

The results will be published during Oracle Open World.
As I’m interested in this topic(Forms and Forms Modernization) and doing a presentation on Oracle Open World about Oracle Forms(session 08262 “What’s Your Choice for Oracle Forms: Modernize, Upgrade, Integrate, or Migrate?”), I’m looking forward to the results of the survey!

The aim of All Things Oracle is to provide a gateway to the wealth of information and material available for Oracle developers and DBAs.
The site brings articles and other resources of Oracle experts.
Just to name a few:

• Alex Nuijten -Database Development – Oracle Ace Director
• Cary Millsap – Software Development – Oracle Ace Director
• Dimitri Gielis – Oracle Application Express – Oracle Ace Director
• Martin Giffy D’Souza – Oracle Application Express – Oracle Ace
• Roel Hartman -  Oracle Application Express – Oracle Ace Director
• Scott Spendolini – Oracle Application Express – Oracle Ace Director

All very experienced experts that will bring interesting articles!

I will also contribute to this site.
My specialities are SQL, PL/SQL, Forms and Forms Modernization, so expect articles on these topics in the near future on All Things Oracle.