Fedora SQL*Developer

After you download SQL Developer 18 on Fedora 27, you can install it with the yum utility, like

yum install -y sqldeveloper-

The installation should generate the following log file:

Last metadata expiration check: 2:26:23 ago on Sat 25 Aug 2018 07:10:16 PM MDT.
Dependencies resolved.
 Package               Arch            Version                      Repository             Size
 sqldeveloper          noarch            @commandline          338 M

Transaction Summary
Install  1  (more...)

APEX New Workspace

After you install APEX or upgrade a base APEX, you need to create workspaces. These instructions show you how to create a workspace in APEX 18. You have two options, you can use the base url while specifying the INTERNAL workspace.

  1. You start the process by accessing the Oracle APEX through the standard form by entering the following URL:


    • Workspace: INTERNAL
    • Username:  ADMIN
    • Password:  installation_system_password

  1. The better approach is to use the (more...)

APEX 4 to 18 Upgrade

While preparing my new instance for class, which uses Oracle 11g XE and Fedora 27, I got caught by the Oracle instructions. I should have got caught but when you’re in a hurry sometimes you don’t slow down enough to read it properly. Actually, for me it was the uppercase APEX_HOME that threw me for a moment. It looks too much like an environment variable. Step 5 of the upgrading instructions says:

  1. Log back into (more...)

MySQL 5.7.* and mysqli

After installing MySQL 5.7.22 and PHP 7.1.17 on Fedora 27, you need to install the mysqli library. You need to verify if the mysqli library is installed. You can do that with the following mysqli_check.php program:

Check mysqli Install
< ?php if (!function_exists('mysqli_init') && !extension_loaded('mysqli')) { print 'mysqli not installed.'; } else { print 'mysqli installed.'; } ?>

You test preceding PHP program with the following URL in a browser:


If the mysqli program isn’t installed, you can install it as follows by opening the yum interactive (more...)

Docker on Fedora 27

This walks you through the steps to install the Community Edition of Docker on Fedora 27. If you’ve been living under a rock for a few years, Docker is an open source container virtualization software.

Docker or Docker Community Edition is a necessary step if you want to install something like Microsoft’s SQL Server on Fedora because only these are supported platforms:

  • Red Hat Enterprise Linux 7.3 or 7.4
  • SUSE Linux Enterprise Server (more...)

Ruby GEM Mongo

While trying to use the Ruby gem utility to install the MongoDB gem, I encountered an error on a new Fedora 27 instance. This is the error message:

Fetching: bson-4.3.0.gem (100%)
Building native extensions.  This could take a while...
ERROR:  Error installing mongo:
        ERROR: Failed to build gem native extension.

    current directory: /usr/local/share/gems/gems/bson-4.3.0/ext/bson
/usr/bin/ruby -r ./siteconf20180517-49401-1htl7zc.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/share/include/ruby.h


Cassandra on Fedora 27

The last time that I installed Cassandra was on a version of Fedora 20. So, I new the first thing to check was the installation of Java. You can check the Java installation with two statements on a fresh installation of Fedora 27. You need to check the Java runtime and then the Java Software Development Kit.

You check the Java runtime with this command:

java -version

It should return:

openjdk version "1.8.0_171"

MongoDB on Fedora 27

I was very pleased to see MongoDB 3.4 in the repo for Fedora 27; however, I was quite frankly severely disappointed by the lack of concrete installation steps in the MongoDB in Action, Second Edition. The installation is straightforward as long as you remember that you don’t simply install a mongodb package. You need to install the mongodb and mongodb-server packages as well as some dependents.

As the root user, you can use yum (more...)

MySQL on Fedora 27

While updating my class image to Fedora 27, I noticed that it installed the Akonadi Server. The documentation on the Akonadi server lacked some straightforward documentation. It also offered a bundled set of software that limited how to approach MySQL development.

So, I removed all those packages with the following syntax:

dnf remove `rpm -qa | grep akonadi`

After removing those Akonadi packages, I installed the MySQL Community Edition from the Fedora repo with this (more...)

PostgreSQL Calling File

Somebody asked: How do you run a script file from PostgreSQL’s psql prompt? I created two files to answer the question. Here are the two files:

Static File

SELECT 'Hello World!';

Dynamic File

SELECT 'Hello ['||current_user||']!';

It’s a simple solution, you put a \i or \include before the script file name, like:

\i helloworld.sql


\include hellowhom.sql

I hope this helps those trying to call SQL script files from an interactive psql session.