While installing Oracle on computers which have more than 1 GB of RAM sometimes gives you an error while creating the database. Oracle gets installed successfully but while running the Database configuration assisstant, it throws an error and installation fails.

The error shown will be something like cannot allocate x bytes of shared memory. The error messages are very misleading. If you check the logs, it shows that the wizard was unable to start the oracle engine.

After spending days scratching my head, I finally found the solution. The system on which I was working had 2 GB of RAM. In case you remove 1 GB, the database gets created. Now that is not an option!

So further investigating, I found a simple solution. Rather than choosing a typical installation which installs a standard database, you should choose to install the custom installation. Now when the Database configuration assisstant runs at the end of the installation, it will ask you for the database parameters. You can leave all the standard options selected without making any changes in the initial screens. Towards the end, you will come across an option whereby you can set the Database block size. This will be shown as equal to 8192 Kb. Simply modify this figure to 4096. Leave all the remaining options unchanged. And now your database will get easily created!