Linux User-Group Console

This post shows you how to add the menu option and GUI to set users and groups. It’s quite a bit easier than mastering all the command-line syntax. It makes setting up the required user and group accounts for an Oracle Enterprise or MySQL database solution much easier.

You add the utility by calling the yum (Yellowdog Updater, Modified) utility like this:

yum installed -y system-config_users

You should see the following:

Loaded plugins: langpacks
Usage:  (more...)

CBO Transformationen für count distinct Operationen

Anfang 2014 hatte ich hier einen Artikel angesprochen, der im High-Performance Blog von Persicope erschienen war und versprach, postgres Queries mit einer count distinct Operation um den Faktor 50 zu beschleunigen. Ich hatte damals selbst ein paar Tests mit Oracle durchgeführt, die zeigten, dass die Umformulierung auch dort nützlich ist, aber weitaus weniger dramatische Effekte hervorruft als bei postgres (was kurz darauf in einem weiteren Artikel bei Periscope ebenfalls angemerkt wurde. Außerdem hatte ich einen (more...)

I/O Resource Management on Exadata

Consolidation is a key enabler for Oracle database deployments on both public and private clouds. Consolidation reduces the overall IT costs by optimizing the operational and capital expenses. In addition, it enhances the effective utilization of cloud resources. The Exadata database machine has been optimized to run schemas and databases with mixed workloads together, making … Continue reading

INSERT ALL caveat

Why you might want to think twice about using INSERT ALL.

One of those things I knew and then forgot.

So, let’s say you’ve got three tables or a partitioned table or something like that.

Let’s use regional tables for simplicity.

drop table t1_r1;
drop table t1_r2;
drop table t1_r3;

create table t1_r1
(col1 varchar2(2) not null
,col2 number not null
,check( col1 in ('R1')));

create table t1_r2
(col1 varchar2(2) not null
,col2 number not  (more...)

Dropping constraint… what about the index?

In a recent release that I’ve been working on, we had to drop and recreate some of the unique/primary key constraints (due to columns being added into the constraint) on some of our tables.

Prior to working in this team, I had only ever come across explicitly creating the indexes for a table, similar to:

create table test_explicit_index (col1 number,
                                  col2 varchar2(30),
                                  col3 date);

create unique index col1_exp_pk on test_explicit_index (col1);

We can see the (more...)

#Kscope16 Blog Hop: #BigData and #AdvancedAnalytics Sessions Not to Miss

Need help choosing sessions for #KScope16? Here are my Top 5 for the #BigData track

Oracle CURRENT_TIMESTAMP Function with Examples

The CURRENT_TIMESTAMP function is one of the many time and date-related functions in Oracle. Learn how to use it and see some examples in this article. Purpose of the Oracle CURRENT_TIMESTAMP Function The Oracle CURRENT_TIMESTAMP function will display the current date and time. It’s displayed in the session time zone, which is the timezone of […]

Protected: easyJet Request for reimbursement and expenses, reference: EQ7818W

There is no excerpt because this is a protected post.

Fix VMware Networking

Occasionally, my students loose their network connection when copying their virtual machines. This article shows you how to rebuild your Internet connection.

The first step requires you to identify the port number on your host operating system, which is typically Windows OS or Mac OS X. You can find that by running the following search from a Mac OS X Terminal session or Windows OS Command session.

If you’re on the Mac OS X, you (more...)

APEX Survey Results: What development resources?

The next question in my 2015 survey was a high level look at what resources developers use to get through your day.

On a slightly side note, there was an interesting discussion on the science of preferred vs effective learning styles in this podcast. It reminded me of my scuba diving course where we learnt the content using 5 different methods, which was a great way to ensure everyone understood how to survive in a (more...)

More on CSS selector performance in Oracle APEX

Last month I wrote a post about CSS performance, including some performance test results.

I recently encountered this brilliant post on Medium that describes some best practices for CSS.

While APEX does a lot of this for you, I think it's worth a read by all developers. Even applying basic naming conventions can make code easier to read and understand.

There was also a section on performance that described an issue that my previous (more...)

Small tip: Align button in UT

Ever had this problem where your button is offset to page items?

Item / Button misalignment

While the Universal Theme is awesome, it hasn't quite got everything right. I look forward to trying the updated version of the theme in our existing applications.

APEX forum legend fac586 (a.k.a. Paul MacMillan) provided a simple solution here.


Add t-Form-inputContainer to the Column CSS Classes property for the button.

Little tips like this can be acquired (more...)

Oracle CREATE TABLE Syntax and Examples – The Complete Guide

Creating database tables in Oracle is one of the most common tasks an Oracle developer or Oracle DBA does. Learn how to create tables, what the syntax is, and see some examples in this article. What Is The Create Table Command Used For? The CREATE TABLE command is used to create a database table. It […]

Optimizer-Features unterschiedlicher Oracle-Versionen vergleichen

Nigel Bayliss stellt im Blog der Oracle Optimizer Entwicklung ein nützliches Skript vor, mit dessen Hilfe man die Optimizer Features unterschiedlicher Oracle Releases vergleichen kann. Das Skript legt diverse Hilfstabellen an und greift auf v$session_fix_control, sys.x$ksppi und sys.x$ksppcv zu, für die man demnach Lesezugriff benötigt. Kann man natürlich auch von Hand machen, aber ein passendes Skript macht dergleichen komfortabler.

Oracle BITAND Function with Examples

In this article, I’ll explain how to use the Oracle BITAND function and show you some examples. Purpose of the Oracle BITAND Function The Oracle BITAND function is used to perform what’s called a standard bitwise AND operation. It’s used to compare two numbers and outputs a third number. I’ll explain what a bitwise AND […]

Rounding amounts, divide cents over multiple lines

In previous articles I wrote about dealing with a missing cent when you need to divide a certain amount over multiple lines. In these articles, links are at the bottom, I described a method to calculate the difference on the last row.
Then a question arose (as a comment):
What if for example i have 42 records and i wish to divide 100 by 42. I would get a rounded value of 2.38. If (more...)

12 Game of Thrones Career Lessons You Can Benefit From

The popular fantasy show has many characters and plot lines. We can learn a lot from them on how we can improve our career. Game of Thrones is probably the best show I’ve ever seen. Every week, my girlfriend and I watch it, glued to the screen for an hour and then we eagerly await […]

Debug PL/SQL Web Pages

What happens when you can’t get a PL/SQL Web Toolkit to work because it only prints to a web page? That’s more tedious because any dbms_output.put_line command you embed only prints to a SQL*Plus session. The answer is quite simple, you create a test case and test it inside a SQL*Plus environment.

Here’s a sample web page that fails to run successfully …

1
2
3
4
5
6
7
8
9
10
11
 (more...)

Subtleties – Part 2 (Nested Tables and Varrays)

In Part 1 we saw that the SQL function COLLECT with the DISTINCT option is not natively supported in PL/SQL.
One suggested workaround was to apply the SET function on the result of the “simple” COLLECT function (without the DISTINCT option).
This works fine, in both SQL and PL/SQL, as long as the collection type that we use is Nested Table.

create type integer_ntt as table of integer
/

select person_id,set(cast(collect(project_id) as integer_ntt)) project_id_list
 (more...)

SQL Developer & PL/SQL

While SQL Developer installs with a dbms_output view, some organizations close it before they distribute images or virtual machine (VM) instances. This post shows you how to re-enable the Dbms Output view for SQL Developer.

SQL Developer DBMS_OUTPUT Configuration

SQLDeveloper1

  1. You need to open SQL Developer, which may look like this when the DBMS_OUTPUT view isn’t visible.

SQLDeveloper1

  1. You need to click on the View menu option in SQL Developer and choose the Dbms Output dropdown menu (more...)