DBCA - useWalletForDBCredentials 19c

You can use Oracle wallet as a secure external password store for authenticating database users in DBCA silent mode commands. Oracle wallet is a secure software container external to Oracle Database, which can be used to store authentication credentials of Oracle Database users.
The configuration of the Oracle wallet as a secure external password store will be done by the mkstore command-line utility.

Database User Authentication in DBCA Commands Using Oracle Wallet

• useWalletForDBCredentials
  Specify true to use Oracle wallet for database user authentication, else specify false.
  Default is false.
• dbCredentialsWalletLocation
  Directory in which the Oracle wallet files are stored
• (Optional) dbCredentialsWalletPasswordPassword for the Oracle wallet account user. If the Oracle wallet is auto-login enabled, then you need not specify this password

Configuring Read Only OracleHome - 18c

Starting with Oracle Database 18c, you can configure an Oracle home in read-only mode. In a read-only Oracle home, all the configuration data and log files reside outside of the read-only Oracle home. This feature allows you to use the read-only Oracle home as a software image that can be distributed across multiple servers.

The concept of a read-only Oracle home, Oracle has committed to to separate configuration files from binaries. The Configuring Read Only OracleHome 18c have impact on the following methods / DBCA / Patching / Upgrade / Key stores

Using DBCA to create a standby database

In Oracle 12.2 there is a new feature added to the dbca commando. One of the new feature is creating a standby database [DBCA Standby Creation].  At the Standby server install the Oracle Software and start a listener. And start the command "dbca -silent -createDuplicateDB -createAsStandby".

This dbca command will create a standby database,and  nothing more.
Get the new standby database operational as a standby database additional steps must be performed.
The steps are conform the steps  for building a standby databases.

Lets play with the DBCA option for creating a standby database.

Create Database using dbca result: TNS-04612: Null RHS for service_name

When creating a (cluster) database using DBCA it can result into an error. One of those errors can be TNS-04404, TNS-04414 & TNS-04612 errors. Testing the service with tnsping or sqlplus works fine.

TNS-04414: File error caused by: TNS-04612: Null RHS for “service_name”