Views

Patrick Barel on 05 June 2013 with 0 comments

Success always occurs in private and failure in full public view. – Unknown When working with views you have several options to hide some of the data. Of course there is the possibility not to select certain columns of data in the view. This way, the user of the view doesn’t even have to know this column even exists. You… Continue Reading →

PL/SQL Subtypes

Patrick Barel on 03 April 2013 with 5 comments

Technology is dominated by two types of people: those who understand what they do not manage, and those who manage what they do not understand – Putt’s Law We are always working with data and their datatypes. In the tables we constrain the data by their datatype. For instance, we create a price column of type NUMBER(4,2) telling the database… Continue Reading →

Custom Authentication in APEX

Patrick Barel on 09 January 2013 with 20 comments

  Trust is a great force multiplier. – Tom Ridge When you build a web application you have two choices for the pages: they can either be public or protected. Mostly you will build applications using a combination of the two. Some pages will be publicly available, like the landing page of your application, but there will also be pages… Continue Reading →

Edition Based Redefinition – Part 2

Patrick Barel on 06 November 2012 with 0 comments

Greatness is a transitory experience. It is never persistent. – Collected Sayings of Muad’Dib by the Princess Irulan In the previous article we saw how we could have different version of the code in different editions of the schema. But what about the tables? They are not editionable? This article will show you how to work ‘around’ that. Data Most… Continue Reading →

Edition Based Redefinition – Part 1

Patrick Barel on 25 October 2012 with 0 comments

A process cannot be understood by stopping it. Understanding must move with the flow of the process, must join it and flow with it. – Frank Herbert, Dune (First Law of Mentat) One of the ‘killer’ features of the Oracle Database version 11g Release 2 is probably Edition Based Redefinition. This functionality allows for near zero downtime when performing an… Continue Reading →

Checking for NULL with Oracle SQL

Patrick Barel on 30 August 2012 with 7 comments

The art of doing mathematics consists in finding that special case which contains all the germs of generality. David Hilbert One of the most mindboggling values in the Oracle database is the NULL value. What is NULL? NULL is nothing. NULL is not even the same as NULL. NULL is undefined. But you need to work with NULL values (which are no… Continue Reading →

ANSI SQL

Patrick Barel on 18 July 2012 with 10 comments

  if you can’t beat them, join them. Gregory Y. Titelman Since Oracle 9i, Oracle SQL supports the ANSI SQL syntax. It takes a bit of getting used to, especially when you are familiar with the Oracle syntax, but it is much more verbose, self-documenting, if you will. Syntax Part of the Select syntax is the joining of tables. To join… Continue Reading →

Kscope12

Patrick Barel on 02 July 2012 with 0 comments

Just back from a full week in San Antonio for KScope12. I really had a good time. ODTUG provides us with the best conference for developers in the world. Seen some great sessions, met up with some old friends, made a lot of new ones, met in real life with some people I knew only from the internet. On Saturday I went to… Continue Reading →

Caching Part 2

Patrick Barel on 23 February 2012 with 6 comments

Never trust a computer you can’t throw out of a window. Steve Wozniak Deterministic Function Caching A function is considered deterministic if the outcome is the same if the input values are the same. Another thing is that the program should have no side effects. All the program changes are the return value and any out parameters. It is because… Continue Reading →

Caching Part 1

Patrick Barel on 14 February 2012 with 0 comments

To err is human, but to really foul things up takes a computer. – Farmers’ Almanac (1978) While programming in the Oracle Database you interact a lot with the data in the tables. Retrieving this data from the database involves context switching between the PL/SQL Engine and the SQL engine. This takes up a relatively large amount of time. You… Continue Reading →