How to enable auto start/shutdown for Oracle Database 18c Express Edition on Linux

Oracle Database 18c Express Edition can be enabled for automatic startup and shutdown with the Linux operating system. This will not only allow you not to worry about starting and stopping the database but it will also ensure that the database is properly shutdown before the machine is powered off. Enabling auto startup/shutdown is done via two simple commands:

systemctl daemon-reload
systemctl enable oracle-xe-18c

These commands will have to be executed either via the root user or with root privileges:

[root@localhost ~]# systemctl daemon-reload
[root@localhost ~]# systemctl enable oracle-xe-18c
oracle-xe-18c.service is not a native service, redirecting to /sbin/chkconfig.
Executing /sbin/chkconfig oracle-xe-18c on

For more information about starting and stopping Oracle Database XE, have a look at the documentation.

How to install Oracle Database 18c XE on Linux

The new version of the free Oracle Database edition, Oracle Database 18c Express Edition, just got released for Linux 64-bit. Getting started is really simple on Oracle Linux, basically a three step process of downloading the RPM file, installing it and then configuring the database. On other Red Hat compatible Linux distributions you will also have to download the Oracle Database Preinstall RPM alongside the XE RPM file. Here is a quick guide on how to setup Oracle Database 18c XE.

tl;dr

Oracle Linux

Download the RPM file from Oracle Technology Network
Run “yum -y localinstall oracle-database*18c*“
Run “/etc/init.d/oracle-xe-18c configure“

Other Red Hat compatible Linux distribution

Download the RPM file from Oracle Technology Network
Download the Oracle Database Preinstall RPM via “curl -o oracle-database-preinstall-18c-1.0-1.el7.x86_64.rpm https://yum.oracle.com/repo/OracleLinux/OL7/latest/x86_64/getPackage/oracle-database-preinstall-18c-1.0-1.el7.x86_64.rpm“
Run “yum -y localinstall oracle-database*18c*“
Run “/etc/init.d/oracle-xe-18c configure“

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Oracle Database 18c Express Edition is Generally Available!

Oracle just released the new version of Oracle Database Express Edition (XE), a free edition of Oracle Database. This release means something special to me, as I have been closely involved in it and with the great team that brought us Oracle Database 18c XE.

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Creating an Oracle Database Vagrant box

Oracle recently launched a new GitHub repository for providing people with Oracle software inside Vagrant boxes. If you have ever setup an Oracle database inside a VirtualBox VM, whether it is as your sandbox environment, to explore Oracle database, or to use it as a full-on development environment, things have just gotten a lot easier for you. With Vagrant, you can now provision an Oracle database inside VirtualBox in a matter of a couple of simple steps.

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Creating an Oracle REST Data Services Docker image

Oracle has added Oracle REST Data Services (ORDS) to the Docker build files family on GitHub, which means that you can now easily dockerize ORDS. If you don’t know yet what ORDS is, it’s a free technology from Oracle that allows you to REST-enable your Oracle databases. More specifically, with ORDS you can just fire off regular REST calls to modify or retrieve data from one or many Oracle databases without having to know how to write SQL; not that knowing SQL is a bad thing! 🙂 In modern application and microservices architectures REST has become more and more popular for exchanging information. ORDS enables you to easily exchange data from and to Oracle databases via REST without having to write lines and lines of code yourself. For more information on what ORDS is and what it can do, check out Jeff Smith’s blog post about ORDS.

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Manually installing a Maven artifact in your local repository

I find myself once again in the situation that I have to install the Oracle JDBC driver into my local Maven repository. Usually this is easily accomplished via mvn install:install-file -Dfile=<path-to-file> -DgroupId=<group-id> -DartifactId=<artifact-id> -Dversion=<version> -Dpackaging=<packaging>, see Guide to installing 3rd party JARs for more details on that. However, this time I was thinking to go the extra mile and actually figure out a way of how to do it entirely manually. This comes in handy if you have, for example, Maven integrated in your IDE and the mvn binary not available to yourself in the command line.

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How to create small Docker images

Oracle_Docker When it comes to space efficiency Docker still isn’t quite as good as it could be. The layered filesystem used by Docker sometimes occupies more space than is really necessary. Over time, a couple of enhancements have made their way into Docker to allow the build of more space efficient images. The ADD instruction for example is smart enough to detect (unfortunately only) local compressed archives (and unfortunately only identity, gzip, bzip2 or xz but not zip archives) and directly adds the uncompressed contents into the image, unlike the COPY instruction that simply copies a file into the image. The downside of the latter is that space is occupied for the zip archive itself and the extracted contents of the archive, whereas the former will not occupy any space for the archive as it is never added into the image.

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Why you should never put objects into the SYSTEM or SYSAUX tablespace

Just because you can doesn’t mean you should

I still see it happening that people put object, i.e. tables, etc. in the SYSTEM or SYSAUX tablespace. Sometimes it’s done deliberately, sometimes it happens automatically by creating a table in the SYS schema. Well, let me tell you, it’s a really bad idea. You should not put any kind of user object into those tablespaces. Even the Oracle Database Documentation warns you of doing so:

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Creating an Oracle Database Docker image

Run your Oracle database inside a Docker container

Oracle_Docker

Oracle has released Docker build files for the Oracle Database on Github. With those build files one can go ahead and build his or her own Docker image for the Oracle Database. If you don’t know what Docker is you should go and check it out. It’s a cool technology based on the Linux containers technology that allows you to containerize your application, whatever that application may be. Naturally, it didn’t take long for people to start looking at containerizing databases as well which makes a lot of sense, especially for, but not only, development and test environments. Here is a detailed blog post on how to containerize your Oracle Database by using those build files that Oracle has provided.

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Oracle 12c R1 background processes

Here is yet another Oracle 12c post to add to all those out there and this one starts with a question: How many background processes exist in an Oracle DB 12.1 environment to date? Just take a moment and take a guess, if you haven’t already seen the bold number coming up. The answer is: 108! That is with all the available bells and whistles turned on but it gives you an idea of how much engineering has gone into the Oracle Database over all those 30+ years. In Oracle 12c there is a total of 19 new background processes meaning that if you are running in an 11gR2 environment you will only have 92. Wait, 92? 108 – 19 = 89 and not 92. Those numbers don’t add up so what happened? It is one of those questions I get these days when talking about 12c. Although you can’t change it anyway people want to know what has changed between the versions and I guess: Fair enough. So there you have it, the reason for this post: To share my little research and perhaps answer the same question from one or two people out there before it reaches me via other channels. Or worst case, a link that I can copy/paste rather than having to type this all over again. Continue reading “Oracle 12c R1 background processes”