Month: September 2011

Are You Ready? Upcoming Conference in Perth

Just a quick note to draw attention to the lineup for AUSOUG National Conference – 3-4 November at the luxurious Burswood Resort here in Perth. The usual suspects will be there, for example:

Signs of the coming Apocalypse? Who knows….

Plan your trip (and arrange your accommodation early, if you need it) and your conference schedule today!

Installing Oracle 11gXE on Amazon Elastic Cloud

There is officially now no good excuse for not running your own instance of Oracle 11g and getting into Apex 4 development, or just playing with SQL and PL/SQL.

Note: another easy-to-follow guide to this process was published back in April by Alex Gorbachev here:, which may suit your needs – although it is based on an AMI with a beta release of 11gXE pre-installed. Some of the instructions below are virtually identical to his.

1. Gather your software.

You’ll need:

What, no OS, you ask? Nah – the easiest way to get started is to start with an AMI (Amazon Machine Image) that has linux installed.
Install PuTTY and your SCP/SFTP client on your computer, then:

2. Get your Amazon EC2 account.

Go to and click “Sign Up Now”. You’ll need an EC2 account and you’ll need to give them some credit card details.
Navigate to the Amazon Elastic Compute Cloud (EC2) in the AWS Management Console.

3. Launch Instance.

Click the “Launch Instance” button. Go to “Community AMIs“. Change the “Viewing” filter to “64-bit“. In the search field type “oracle“. You should see a long list of AMIs to choose from. What you’re looking for is an EBS-backed AMI running Oracle Enterprise Linux 5. The actual name and AMI ID will vary from region to region, but in US-East you could use “493731438004/Oracle Linux 5.6 x86_64 – OVM”, AMI ID ami-42778a2b (you could enter this ID into the search field to go directly to it), or if you’re using the Singapore region you could use AMI ID ami-bc2f56ee.
Next, you get to choose the size of the instance. The bigger the machine, the more grunt you get, but also slightly more expensive to run. You could choose Micro, but you might find it a bit slow at times. Of course, there’s nothing stopping you from trying one, and if you don’t like what it offers, just trade up!
On the “Advanced Instance Options” page, accept all the defaults and Continue.
On the next page, you can put a name on your instance if you like. This is just a label, and comes in handy when you run many instances.
On the “Create Key Pair” page, you need to select a Key Pair. You can create one if you don’t already have one.
Enter a name for your key pair, then click “Create & Download your Key Pair“. Make sure you keep the file (it’ll be a .PEM file) in a safe place – if you lose it, you’ll lose access to your instance (in which case you’d just have to terminate it and start again).
The next page is the “Configure Firewall” step, where you select a Security Group. You could create a new one if you like – open up TCP ports 22, 8080 and 1521 so you can upload files, access the Apex web interface, and connect to the database (e.g. from SQL Developer).
On the final page, click “Launch”. After maybe a minute or two, your instance will have been started and running, ready for you to connect to it and do stuff on it:

Here, you can find the following useful information:
Status: this will say “Pending”, “Running”, or some other status.
Public DNS: this is the URL you can use to connect to your instance: in my case, it is

4. Set up your key pair.

Before you can connect to your instance with PuTTY or your SCP client, you’ll need a PPK file. You generate this from the PEM file you got before. In the folder where PuTTY is installed is a little tool called PUTTYGEN.EXE. Run this, select Conversions -> Import Key, select your PEM file, then click Save Private Key. It might warn you about a passphrase – if you want to protect the key in case someone manages to steal it then you could put one in, but personally I don’t. Save it somewhere safe as a PPK file.

5. Upload the Oracle installer to the instance.

Open WinSCP. Click New. Copy the Public DNS into Host (e.g. Set User name to root. Leave the Password blank. Select your Private Key file (PPK). Save the settings then click Login. If you get a warning about the “server’s host key not in the cache”, just click “Yes” to continue.
If you get timeout errors, check that port 22 has been open (and your changes saved) on your AWS Security Group.
Upload the Oracle installer (

6. Login to your instance.

Open PuTTY. Copy the Public DNS into Host Name, and select your Private Key file (PPK) (this option is tucked away under Connection/SSH/Auth). You can save the session if you want. When you Open the connection, it will prompt for the login. Login as root.

7. Install Oracle.

You can follow Oracle 11g XE installation instructions to install and configure Oracle, which honestly are really easy and straightforward:

If you just want to know what to type, here is basically all you need (type the commands after the “#” – don’t type the “#” itself though):

# unzip /root/
# rpm -ivh /root/Disk1/oracle-xe-11.2.0-1.0.x86_64.rpm
# /etc/init.d/oracle-xe configure

This script will prompt you for the Apex port and the database port – just press Enter to accept the defaults (8080 and 1521, respectively). It will then ask for the password for SYS and SYSTEM. Finally, it will ask you if you want it to run on startup. Accept the default (yes).

8. Disable the firewall.

# chkconfig iptables off
# service iptables stop

This disables the internal firewall running in your linux instance.

9. Log into Apex.

Open your browser and point it at your instance. Take the Public DNS and add :8080/apex/apex_admin, e.g.:

The login name is admin, and the password is (for now) the same password you entered for the SYS and SYSTEM accounts earlier.

It will prompt you to change the password. It has to be a fairly secure – you’ll need at least a letter, number and symbol, and you can’t include the login name. After changing your password, you’ll need to log in again but using the new password.

You now have a fully-fledged Oracle Application Express environment, version 4.0.

10. Create a Workspace.

The last thing you need to do before you can start creating applications and stuff is to create a workspace. Click “Create Workspace” and answer the prompts to create the workspace along with its own schema and admin user account.

Log out of Apex Administration, and log into the newly created workspace – and you will now be able to start creating applications, tables, and what-have-you. You can also use Apex to write code (such as procedures and packages), but I suggest you use Oracle SQL Developer for this kind of thing because it’s a bit more powerful.

From now on, to get back into your Apex development environment, you can use this url:

Have fun!
Oh, by the way: when you’ve had your fun, and you want to stop your instance (which at about 34c/h may cost around $60 per week if you leave it running 24×7), don’t forget to terminate it from AWS Management Console. Before you do, however, you can take a snapshot of it in its current state so you can restore from it later. (Before this, you might want to shut down the Oracle database within the instance first – although I’ve found it quite easy to recover an instance which was snapshotted while the database was up and running). To do that, right-click on the instance in AWS Management Console, and select “Create Image (EBS AMI)”. It may take some time for the image to be created. When the image creation is complete, you can then Terminate the instance. The AMI will take up a bit of storage that will cost a dollar or two per month; and you can now spin up as many copies of your machine whenever you want.


Lew posted an excellent introduction to PuTTY and SSH for AWS Newbies that I heartily recommend. It was posted in 2009 but still applies.

MERGE to table with Virtual Columns + Error Log Table = ORA-03113

This is just in case you come across this. It appears to be an Oracle bug. I don’t know if it’s been fixed in a later release. I haven’t isolated a simple repeatable test case yet, so I don’t know if the scenario here includes all the relevant details or not.

Version: Oracle Database 11g Enterprise Edition Release – 64bit Production


  • MERGE into a table that has one or more virtual columns.
  • The MERGE statement has a “LOG ERRORS” clause.
  • The error log table is a standard one created using DBMS_ERRLOG.create_error_log.

Other factors that may or may not be involved are:

  • the target table is in a different schema
  • the merge statement queries another table with the same name in the current schema
  • the merge statement has a WHERE clause on the WHEN NOT MATCHED clause


ORA-03113: end-of-file on communication channel and/or ORA-03114: not connected to ORACLE

This happens whether the MERGE is executed or just explain-plan’ed – so it shouldn’t be related to the actual data in either the source or destination tables.


After creating the log table, but before the merge, drop the columns from the error log that are virtual columns in the target table.