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Using the Database Configuration Assistant- Creating a Database-1

If you are running DBCA utility right after the Oracle software installation, many of the environment variables will already be set, and the prerequisite steps will already be completed. But if you decide to take lunch or a coffee break first, validate the ORACLE_ HOME and DISPLAY variables and then run the configuration assistant.

$ echo $ORACLE_HOME $ echo $DISPLAY

$ dbca

There are two creation modes for creating a database in DBCA. One is the typical configuration, and the second option is advanced configurations. As you might already guess, the typical configuration does not require much information. You need to provide a database name, storage, and password, as shown in Figure 2-1.

Figure 21. DBCA creation mode

In the typical configuration mode, the next screen summarizes the database that is going to be created. In Oracle 23c, it will create a container database (CDB), and you need to provide a pluggable database (PDB) name. The container and pluggable databases are multitenant databases, which is different than in previous releases. In 19c and prior releases, you could still create a non-CDB database, but this option is no longer available in 23c and has been removed since 21c. This slightly changes how DBAs manage the databases and can even break up the tasks into system DBAs and application DBAs more than done previously. We will cover this in later chapters, but for now it is important to know for database creation that you are creating a CDB with a PDB. The CDB will be the root database for most system functions, and the PDB will contain application and user schemas and objects. This might seem like a big shift in managing the database, but it does separate the system and application parts of the database. The shared resources and processes will be part of the CDB, and the PDB will have users, tablespaces, and objects. There is also a separation of duties with permissions and settings at the PDB level instead of just at the CDB level. Again, we will get into more details of how to start and stop the databases, backup and recovery, and the differences for these tasks at the CDB and PDB levels. Figure 2-2 shows the summary of the database creation. Don’t forget to create a response file here to make sure you can use it later in other database creations.

Figure 22. DBCA summary

The advanced creation mode allows for the configuration of templates and parameters. You can then save a new template to use for future database creations with DBCA. After looking at the templates, as shown in Figure 2-3, the database name needs to be entered, and here you can create more than one pluggable database (PDB) as well as decide if you want a local UNDO tablespace for the PDBs instead of a shared one in the CDB.

Figure 23. DBCA advanced creation mode