Unified Auditing in Oracle 18c

Oracle database Unified Audit Trail was introduced in Oracle 12cR1 , as a mechanism to unify different oracle database audits (based on different features) under one view. As you may know “mixed mode” auditing is enabled by default starting with 12cR1 release. One of the limitations when switching from “standard auditing” to “unified auditing” in both Oracle 12cR1 and 12cR2 is you can’t push audits to syslog anymore. This has changed in Oracle 18c, you can push audits to SYSLOG in Unix/Linux OS and to windows event log.

A new init parameter has been introduced “unified_audit_systemlog”



In window OS I have set the parameter as TRUE as shown below:


For simulation through RMAN I have executed command to take controlfile backup then check the windows event log:



Another new feature in 18c , is the ability to export and import unified audit trail !

Command to export:

expdp system/XXXXXXXX full=y directory=DUMP_DIR logfile=exp_unified18c_log.log dumpfile=exp_unified18c.dmp INCLUDE=AUDIT_TRAILS












Oracle 18c new feature: Cloning PDB using DBCA (Database Configuration Assistant)

Here I am cloning a local PDB using DBCA, which is a new feature in oracle 18c:

Go to


Execute the command:


make sure X-windows is configured: export DISPLAY=PCXXXX:0.0


You can use silent installation:

In Linux:

./dbca -silent -createpluggabledatabase -sourcedb ORACLE -createpdbfrom PDB -pdbName PDB_TEST_CLONE2 -sourcepdb PDB_TEST

In Windows:

dbca -silent -createpluggabledatabase -sourcedb ORACLE -createpdbfrom PDB -pdbName PDB_TEST_CLONE2 -sourcepdb PDB_TEST


Upgrading Oracle database from 12cR2 to 18c in Windows

Download the binary for OTN and extract the ZIP file:


Choose “set up Software only” option:


Upgrading existing Oracle database from 12cR2 to 18c

In the unzipped binaries go to “bin” folder then search for dbua.bat file




You will see a list of pre-requisite checks that is being listed, in my case I will hit “Fix & Check Again” option….this will successfully eliminate the check with severity “Error” regarding recycle bin not being purged as shown below:

UP4UP5I accepted the warning message, press “Yes”


DBUA (Database Upgrade Assistant) is providing a rollback (recovery strategy) in case the upgrade fails, you have to choose on of three options:

  • Flashback to guaranteed restore point
  • Full RMAN backup – restore script is also provided as shown below
  • You will be responcible for the recovery strategy


Wait until the upgrade finishes successfully !

After successfully upgrading your Oracle database, you can enable a new feature in 18c called “Read-Only” Oracle Homes .

This feature enables you take a software image, and separating configuration files. Also, it will improve your patching process as the patched (binaries) image can be distributed to other servers.