Overview of Database Configuration Assistant (DBCA)

Database Configuration Assistant (DBCA) is a Java based GUI tool which is very useful to create, configure and drop databases. From 10g R2, this has been enhanced to manage the Automatic Storage Management (ASM) instance. 

Starting DBCA

1. Log on to your computer as a member of the administrative group that is authorized to install Oracle software and create and run the database.

2. To launch DBCA on a Windows operating system, click Start and then select Programs, Oracle - home_name, Configuration and Migration Tools, and then Database Configuration Assistant.

To launch the DBCA on UNIX, or as another method on a Windows operating system, enter the following command at a system prompt:

 The dbca utility is typically located in ORACLE_HOME/bin.

3. The Welcome window appears.

Click Next to continue. The DBCA Operations window appears. 

Options in DBCA

Database Creation

This is the most commonly used option. Database Configuration Assistant (DBCA) is the preferred way to create a database, because it is a more automated approach, and your database is ready to use when DBCA completes. Furthermore, creating or deleting a database with DBCA automatically takes cares of the Oracle Restart configuration that was introduced with 11gR2.

To create a database using DBCA:

Step1 - Start DBCA as described in "Starting DBCA".

In the Operations window, select Create a Database and click Next to start the guided workflow for creating a database. The workflow requests your input in the following windows:

Step 2 - Database Templates  -- Select the type of database to create (General / Transactional /Data Warehouse).
Step 3 - Database Identification -- Setting the Global Database Name and the SID.
Step 4 - Management Options -- Option to Register with Grid Control / Configure Database Control.
Step 5 - Database Credentials -- Setting Passwords for the Administrative accounts.
Step 6 - Database File Locations -- Specifying the type of storage for the database (Location from Templates / Common location for all Datafiles/ Use OMF)
Step 7 - Recovery Configuration -- Specifying Archive mode and Flash Recovery Location
Step 8 - Database Content -- Specify the option to create sample schemas and post creation scripts (if any)
Step 9 - Initialization Parameters -- Specify/Modify the Database initalization parameters (Memory / characterset / Sizing /Connection mode)
Step 10 - Database Storage -- Option to review the storage structure and make changes if required.
Step 11 - Creation Options -- option to create Database/ Template / Generate Database Scripts

More detailed information in Documentation

Database Options Configuration

You can use DBCA to change the configuration of an existing database. For example, you can:

• Register the database with Grid Control
• Configure Database Control alert notification via e-mail
• Enable daily disk backups to the recovery area
• Change default security settings
• Change server mode from dedicated to shared, or the reverse
• Add database options that were not previously configured (for example, Oracle Label Security or Oracle OLAP)

Database Deletion

You can also use DBCA to delete a database. When DBCA deletes a database, it shuts down the database instance and then deletes all database files. On the Windows platform, it also deletes associated Windows services.

Template Management

DBCA templates are XML files that contain information required to create a database. Templates are used in DBCA to create new databases and duplicate existing databases. The information in templates includes database options, initialization parameters, and storage attributes (for data files, tablespaces, control files, and online redo log files).

Templates can be used just like scripts, but they are more powerful than scripts because you have the option of duplicating a database. Duplication saves time because you copy the files of an existing database, referred to as a seed database, to the correct locations.

Templates are stored in the following directory: 

Advantages of Using Templates

• Time saving. If you use a template, then you do not have to define the database.
• Easy duplication. By creating a template containing your database settings, you can easily create a duplicate database without specifying parameters twice.
• Easy editing. You can quickly change database options from the template settings.
• Easy sharing. Templates can be copied from one computer to another.

Types of Templates

Templates are divided into the following types:

• Seed templates
  Containing both the structure and the physical data files of an existing database
• Nonseed templates
  Containing only the characteristics of the database to be created

ASM Configuration

ASM instances were managed by DBCA till 11.1. From 11.2 onwards, the ASM instance management will be performed by ASMCA tool.
This option is used to create and manage the ASM instance. This also helps in creating the Server Parameter file and password files of the ASM instance.
Note that since 11gR2, ASM is included in the Grid Infrastructure which requires its own Oracle Home.

DBCA Modes

Interactive mode

Interactive mode provides a graphical interface and guided workflow for creating and configuring a database. Please refer to Database creation section.

Silent Mode

The following example creates a database by passing command-line arguments to DBCA:

To ensure a complete silent operation, you can redirect stdout to a file. In this case, however, you must supply passwords for the administrative accounts in command-line arguments or the response file.

More details in Oracle Documentation

Debugging DBCA

To trace the DBCA, we need to perform the following.

New Features / Enhancements

The following are the Enhancements to DBCA in 11g.

•  Support to configure new database options
•  Automatic memory management option (Memory_Target)
•  Oracle Data Mining option is made default
•  ORACLE_BASE and Diagnostic Destination configuration
•  Secure database configuration
•  Switching a database from Database Control to Grid Control configuration
•  Automatic Maintenance tasks

Detailed Explanation is available in Note 454631.1 - 11g DBCA New features / Enhancements

Additional Resources

Known Issues and Resolutions