It is best practice to use DBCA template for creating databases on Exadata. When Exadata is deployed using onecommand utility, it also uses Exadata DBCA template to create sample database during deployment. So, let me start by providing you brief explanation about DBCA templates then I will jump on to Exadata DBCA templates.
DBCA templates are XML files that contain information required to create a database. Templates are used in DBCA to create new databases and clone existing databases. The information in templates includes database options, initialization parameters, and storage attributes (for datafiles, tablespaces, control files, and online redo logs). DBCA templates are usually stored in (ORACLE_HOME/assistants/dbca/templates) directory. Even though you can create oracle database manually but there are some advantages of using template including time saving, easy duplication, easy editing and easy sharing. There are 2 types of DBCA templates.
Seed templates: This type of template contains both the structure and the physical datafiles of an existing (seed) database. Your database starts as a copy of the seed database, and requires only the following changes:
- Name of the database
- Destination of the datafiles
- Number of control files
- Number of redo log groups
- Initialization parameters
Non-seed templates: This type of template is used to create a new database from scratch. It contains the characteristics of the database to be created. Non-seed templates are more flexible than their seed counterparts because all datafiles and online redo logs are created to your specification, and names, sizes, and other attributes can be changed as required.
Now for Exadata, as I mentioned it earlier that it is best practice to use DBCA template to create databases on Exadata machine. You will at least found 1 Exadata specific DBCA template on your Exadata machine which got created during your Exadata installation process and you should use that template to create all future databases. If you don’t use Exadata DBCA template to create databases, you will miss out many Exadata best practices and will get low score on your Exachk reports. Running Exachk can help you implement Exadata practices but in order to save time, I will strongly recommended use Exadata DBCA template to create databases on Exadata machine.