Another word for authentication is acces control. Authentication is the mechanism to verify the user’s identity and provide access to a system or application based on the credentials entered by the user. Authorization, on the other hand, says something about the degree of access granted to resources. For authentication, different […]
and now we present… 11g and Apex on Ubuntu
Thanks to a completed messed-up Windows (I managed to demolish my network connections beyond repair) and a helpful tutorial from Dizwell’s blog (thank you oh so very much!) I installed Ubuntu 7.10 (codenamed Gutsy Gibbon) on my laptop, and afterwards, Oracle 11g. I probably wouldn’t have made without Google and […]
Importing Access applications into Apex
Some time ago I’ve been experimenting with the Apex 3.0 feature that migrates entire Access applications to Application Express. It took me a lot of time because I found out the path to it is winding and bumpy. I would like to share some of my issues here. A very good tutorial […]
Check out the Apex 4.0 preview at Carl Backstrom's blog!
The live demo presented by Carl Backstrom as presented to the attendees of the Apex European Training Days is now publicly available! You can review at Carl’s blog , and if you got a few minutes spare time, you should take a look. I think the reporting features of Apex […]
Searching the AMIS Weblog directly from your Firefox searchbar
Why bother using Google if you know you will find the answer on this blog anyway? It would be a nice feature if you could search directly from your Firefox searchbar then, right? Alex just pointed out he already created a plugin before me: https://technology.amis.nl/blog/?p=764 I made one small improvement, […]
How to calculate the Easter date in PL/SQL
Ever wondered how they Easter date is determined? And, even more important, how it is to be maintained in you application. Manually updating the date every year is an option, but it’s always better to calculate it on the fly. It’s not easy because it depends on the age of […]
Creating a shuttlebox in Apex
The changelog of Apex 3.0 mentions something about featuring shuttleboxes. Don’t get too enthousiastic, you still have to do a lot of work yourself. And it’s pretty limited, because this feature assumes the use of static values. That’s not what we want! We want dynamic information from the database! Here’s […]
How upgrading to Apex 3.0 spoiled my weekend!
Allright, that is an exaggeration. Hugely. But it cost me some headache before I realised what was my problem. I still had HTML DB 1.6 running and I thought it was time I upgraded to the only just released version 3.0. So I downloaded the zip-file, and followed the instructions […]
About hierarchical queries, filling the gaps and doing stuff in ApEx
Sometimes you are writing some codes and things really come together well. Let’s imagine, you are writing a little tool in ApEx for registering hours on a project. The hours are recorded in a table which contains all days of the week and a week number (and employeenumber and projectnumber). […]
Removing double records (and keeping one of them)
Assume you have a table with contaminated data (in this example: non-unique values on col1 and col2), for instance because no unique key was implemented. col1 col2 value 2 9 Smith 2 4 Jones2 9 Andersen8 6 Nicholson8 6 Parker If you want to prevent this from happening in the […]
Installation of Oracle Enterprise Linux on VMWare
Recently, Oracle announced and released it’s Enterprise linux. Time to check out what’s it all about! While downloading the software from OTN, I was surprised to see there were no less than 8 discs, I downloaded all of them (a hefty 4.5 gigabytes) and found out after unzipping that the […]
Myths on bitmap indexes
Although bitmap indexes are already available in Oracle 8i or even before (some sources even say 7.3!!!), they are still surrounded by many myths. Time for some clearing up. And believe it or not, every single myth mentioned here I heard many times in several projects.
Setting properties per record in Forms MRB
This is probably described many times before, but you just can’t have enough example code snippets. Imagine you want to restrict users to update records which end-dates are in the past in a Multi record block. Strangely, there is no way you can set the property for a record at […]
Exporting data from Oracle to Excel with ApEx – and vice versa.
If you’re ever asked to export some data from the database into an Excel file (or vice versa), do check if you have ApEx installed on your server. There are some handy utilities available there, especially for end-user tasks. One of these utilities is export to file. To get there, […]
Changing the prompt dynamically in SQL*Plus
This is just a simple trick which is not well-known but makes life easier when using the good ol’ SQL*Plus commandprompt (and many people still do!). If you set the SQLPROMPT environment variabele (either manually or in the login.sql) the standard prompt is replaced by the name of the instance: […]
How does the sequence cache affect performance?
When defining sequences, you can choose to set a cache size or disable the sequence cache: create sequence tst_nc2 start with 1 increment by 1 nocycle nocache; create sequence tst_ch start with 1 increment by 1 nocycle cache 50000; I wondered, does it make an difference in performance? A […]
ApEx 2.2 released
Oracle just released ApEx version 2.2. Here is the list of changes. Most of the changes do not come as a surprise as they were already mentioned in the roadmaps as stated earlier this year. Most interesting new features include the packaged installation, which makes deployment easier. Also Component-level export […]
The UNKNOWN null.
We all are at least a bit aware of the awkward behaviour of NULL in Oracle. But it still is difficult every time we encounter it in a function or where-clause. Some examples to keep in mind when comparing NULL values: 1. null equals what? Null equals nothing, in fact. […]
Open Source Portals and Content Management: Joomla!
Joomla! is open source portal software and content management software in one. The software is easy to install and highly customizable.
CLOB’s unexpected ways
Using CLOBs, conversion to and from VARCHAR2 may give you a headache.
Getting used to Oracle SQL Developer
It took a few months, but I finally start appreciating the Oracle SQL Developer developed by Oracle (The Project Formerly Known As Raptor). There are still some bugs, for instance with debugging through a firewall (hey, didn’t we have the same problem with JDeveloper?) and some features are missing, but […]
DBMS_SCHEDULER as a new alternative for DBMS_JOB
Many people have a dislike of Dbms_job. Setting the right parameters requires good knowledge of the input parameters and you probably need a calculator too! In Oracle 10g, a new package might make things easier.
Need an Oracle client? Do it instant!
Historically, when you wanted to connect to an Oracle database you could not get around downloading and installing a bulky Oracle client. Since 2 years already an alternative exists: Oracle Instant Client. This is the marketingname for a zipfile with all DLL’s necessary for connecting to an Oracle instance. The […]
Ever wondered how Soundex works?
It is not well-known how the Oracle built-in Soundex exactly works. This article explains the basics and also describes the Dutch variation of this algorithm.
Oracle Application Express Roadmap
At the end of january, Oracle announced that Oracle HTML DB was renamed to Oracle Application Express. At the same time they published a roadmap for the next year. This confirms the inside information I had that Oracle takes Application Express serious and keeps developing this development tool. Oracle Application […]
Jonathan Lewis Seminar – Optimising Oracle Performance by Design-
Last week I visited the Oaktable Seminar “Performance by Design” by Jonathan Lewis, held in Utrecht. I would like to share some of the topics of the seminar which I found particularly interesting.
Oracle High Availability Concepts
Audience: DBAâ€™s, infrastructure architects. A brief explanation of the Oracle Dataguard and High Availability concepts.
SVG Viewer for Firefox
The Adobe SVG Viewer is a viewer for Scalable Vector Graphics like charts and graphics and, as I found out, is used by Oracle in web-applications. It’s downloadable at Adobe downloads. However, the plugin only works for Internet Explorer. With some minor tweaks it’s possible to make it available under […]