How to Use the Database Configuration Assistant (DBCA) to Create Databases in Oracle 12c - dummies

How to Use the Database Configuration Assistant (DBCA) to Create Databases in Oracle 12c

By Chris Ruel, Michael Wessler

The database configuration assistant (DBCA) used in Oracle 12c has a lot of screens with all kinds of information. The following steps take you through the process:

  1. Log in as the Oracle software owner.

  2. Go to a command prompt.

  3. Type dbca.

    You see a splash screen and another screen with options.


  4. Select the Create a Database option.

    You are presented with the option of using a default configuration or an advanced one.

  5. Select the Advanced option.

  6. Click Next.

    You’ll see output. Optional database templates are shown:

    • General Purpose

    • Data Warehouse

    • Custom Database

  7. Select the Custom Database option.


    Click Show Details if you want to see the features, parameters, and files chosen by default for each type of database.

  8. Click Next.

    A screen asks you to choose the database name.

  9. Fill in these fields:

    • Global Database Name: Your database name with your network domain attached. If you don’t want to attach your network domain, leave this field blank.

    • SID: This is the short name for your database. It equates to your environment variable ORACLE_SID.

  10. Click Next.

    You’re asked whether you want to manage your database with Oracle Enterprise Manager.


    You can configure this two ways:

    • Configure Enterprise Manager (EM) Database Express: Database Express is a management package that runs locally on the database machine and has many of the features of Cloud Control. However, it controls only one database. If you’re setting up Oracle on a machine with limited resources, you’re going to feel Database Express.

    • Register with Enterprise Manager (EM) Cloud Control: An Oracle software package that typically runs on its own server elsewhere on your network. It can manage many databases, many versions of Oracle, servers, application servers, and even other non-Oracle software, such as Microsoft SQL server, and firewalls.

  11. Select the Configure Enterprise Manager (EM) Database Express option.

  12. Click Next to continue.

  13. Set the database credentials (passwords).

    You have two choices here. You can set the passwords individually for the users that are created with the database or set the same password for all users.

  14. Click Next.

    You’re asked whether you want to register your database with a listener. If you do, choose the correct listener and click Next.

  15. Select an option for how you want to store your files.

    The screen has a drop-down list for you to select how you want to store your files:

    • File System: All your data files are put into formatted drives attached to your computer.

    • Automatic Storage Management (ASM): Don’t choose this now. ASM has some great benefits but isn’t as easy to set up as the DBCA leads you to believe.

  16. Select a place to store your files:

    • File Locations from Template: This option doesn’t let you make any changes. Oracle chooses where to put the files.

    • Common Location: This option activates the grayed-out field. You choose type or browse for a location to store the files.

  17. Choose File Locations from Template and click Next.

    The Fast Recovery Area (FRA) is a storage area that resides on disk which can house backups, archive logs files, control files, and redo log files.

  18. Choose to configure the FRA.

    Doing so simplifies the storage of backups and archive log files.

  19. Determine what FRA space you have available and increase it accordingly.

    The default value is about 5GB. This might be okay for the archive log files of small databases. You can resize the FRA anytime without taking down the database.

  20. Choose to archive later and click Next.

    Archiving adds drain on the system while creating the database. It’s easy enough to enable later on.

  21. Click Next.

    The Memory tab has two options: Typical Settings and Custom Settings.


  22. Select the Typical Settings option.

    Because we’re talking Oracle 12c, selecting Typical Settings sets the memory target as one large chunk and lets Oracle figure out where everything goes.

  23. Click the Sizing tab.

  24. Select the block size.

    If you get this wrong, your only option is to re-create your database (if the performance problems haven’t gotten you fired).

  25. Click the Character Set tab.

    You can change the character set after creating the database, but it’s time consuming and tedious. Select a character set that will house all the characters that your application may use.

  26. Click the Connection Mode tab.

    You have two options:

    • Dedicated Server Mode

    • Shared Server Mode


  27. Breathe.

  28. Click the Customize Storage Button to make storage adjustments.

    Now is a good time to make sure the files spread across multiple mount points. Click each menu: Controlfile, Tablespaces, Datafiles, and Redo Log Groups. Change the directories (on the right) so they’re not all in the same place.

    The screen lists the file and storage objects. The screen currently shows the Controlfile choices.


  29. Click the Close button when you are finished adjusting any files.

  30. Decide if you want to save your decisions as a template for future use.

    If you think you may create a similar database again, this step is a good idea. You can give it a name and a description.

  31. Save everything you did in a set of scripts and decide where you want them.

    It’s a good idea to keep these around just in case. Also, if you’re curious about all the scripting work you just avoided by using the DBCA, have a look.

  32. Decide whether you want to create the database now.

  33. Click Next to go to the summary screen.

  34. Click Finish.

    A screen shows all the options you just chose and the parameters you set.

    The creation status screen appears. A status bar and options also appear. You can watch it go through everything until it’s done.

    When the database is complete, a screen shows the details. A Password Management button lets you unlock or change the passwords of the users that were created as part of the options you installed. All users except SYS, SYSTEM, DBSNMP, and SYSMAN are locked.

  35. Click Exit then Close to close the DBCA.