Skip to main content

ODTUG Kaleidoscope 2008 : Day 1

Today started off with a keynote of Vince Casarez about ‘Web 2.0 meets the enterprise'. He showed some really cool stuff included in Webcenter, like the carrousel (similar to the iTunes coverflow), dynamic charts that were refreshed using push technology. This is the stuff Oracle itself is using for their Fusion apps.

Next John Scott was on for his APEX Hints, Tricks and Best Practices. They were all very useful so I'll list them all 10.

  1. Don't use the default SYSAUX tablespace for the APEX environment, but use dedicated tablespaces instead to make the installation more manageable.
  2. Create specific accounts for all developers, making QA and auditing easier.
  3. Always lock a page when you make changes and document these changes using the comment property.
  4. Use aliases for applications and pages, so f?p=SALES:HOME instead of f?p:117:17.
  5. Use the possibilities of APEX to support re-use of code, like Shared Components, Page 0, UI Defaults and Publish / Subscribe. A little explanation on the last one: If you copy an object you can define it as a subscription to its original. Modifications to the original can then be published to all subscribers.
  6. Use bind variables whenever possible. So don't code WHERE NAME = ‘%P7_SEARCH%', but use :P7_SEARCH instead. So in general:
    • Use :APP_USER in SQL or PL/SQL within APEX
    • Use &APP_USER. within HTML text
    • Use v(‘APP_USER') outside the APEX context
  7. Use database packages to code your PL/SQL.
  8. Don't use HTML markup or CSS in SQL queries: keep presentation and logic separated. Use HTML expressions and templates instead.
  9. Use the Supporting Objects for deployment. There you can define scripts that should run when your application is installed, upgraded or removed. Also use the Build Options, they're great for excluding features that are still on hand.
  10. Be pro-active: use the Application Reports, the Apex Dictionary and Pro-active Monitoring so that you will be the first to know when something is not going the way you expect it to go.

  11. After John I went to (another) Thom Kyte session on 'The Top 11 New Features of Oracle Database 11g'. The most of these features were already familiar to me as I was part of the Logica team that participated in the 11g bèta test. Half of the features were DBA-related, but the features that are most appealing to developers are:

    1. the possibility to cache more using client side caching, server result caching or PL/SQL function result caching;
    2. virtual columns using expressions, constants or deterministic functions (you even can index these columns or use them in a foreign key constraint);
    3. the SQL pivot / unpivot command, so there's no need for the usual max(decode....) ‘trick'.

    In the afternoon Karen en Jan from iAdvise did a presentation on their QA-tool on APEX using the dictionary views. This is a good concept for controlling the quality of your applications on coding style and naming conventions and can be compared with the Headstart quality checks for Designer. They encountered one major technical issue: the battery of the laptop died halfway the presentation, so somebody had to pick up another power adapter.

    David Peake ended the day with an APEX 3.1 overview. To me the interesting part were the last 5 minutes (of his half an hour overdue presentation) where he showed very little of the pre-alfa version of the Oracle Forms Application Migration. With this utility you can read the XML file of a Forms module into Forms Objects in APEX. Then you can change these objects and generate an application. David didn't show the generation part (probably because it didn't work yet) and told that there was ‘some' more work to do, but the APEX team would like to deliver this feature asap... You can expect a whitepaper on OTN about his very soon!
Post a Comment

Popular posts from this blog

Push changed rows to an Interactive Grid

For pushing changes from the database to the end user, the regular solution is using websockets. A change in a record is detected - using a trigger or using the CQN (Change Query Notification) feature - and a notification is send to a websocket server. That websocket server broadcasts the notification over a channel to all browsers that are tuned in to that websocket channel. Then the browser reacts to that notification, usually showing an alert or refreshing a report. This trick is described on multiple sites, just Google for "oracle apex websockets" or similar.

So back in the old days, we used that notification in the browser to refresh the (interactive) report. But along comes the Interactive Grid (IG). While he full-refresh mechanism still works for IG, an IG has also the option to refresh just one row.  So wouldn't it be awesome that just the changed row(s) get refreshed upon a change in the database, instead of the whole report? Can we do it ... yes we can!
First i…

Refresh selected row(s) in an Interactive Grid

In my previous post I blogged about pushing changed rows from the dabatase into an Interactive Grid. The use case I'll cover right here is probably more common - and therefore more useful!

Until we had the IG, we showed the data in a report (Interactive or Classic). Changes to the data where made by popping up a form page, making changes, saving and refreshing the report upon closing the dialog. Or by clicking an icon / button / link in your report that makes some changes to the data (like changing a status) and ... refresh the report.  That all works fine, but the downsides are: The whole dataset is returned from the server to the client - again and again. And if your pagination size is large, that does lead to more and more network traffic, more interpretation by the browser and more waiting time for the end user.The "current record" might be out of focus after the refresh, especially by larger pagination sizes, as the first rows will be shown. Or (even worse) while you…

Dockerize your APEX development environment

Nowadays Docker is everywhere. It is one of the main components of Continuous Integration / Continuous Development environments. That alone indicates Docker has to be seen more as a Software Delivery Platform than as a replacement of a virtual machine.

However ...

If you are running an Oracle database using Docker on your local machine to develop some APEX application, you will probably not move that container is a whole to test and production environments. Because in that case you would not only deliver a new APEX application to the production environment - which is a good thing - but also overwrite the data in production with the data from your development environment. And that won't make your users very excited.
So in this set up you will be using Docker as a replacement of a Virtual Machine and not as a Delivery Platform.
And that's exactly the way Martin is using it as he described in this recent blog post. It is an ideal way to get up and running with an Oracle database …