Understanding Unplug-Plug Upgrades with AutoUpgrade

AutoUpgrade can perform an unplug of a pluggable database (PDB) from an earlier release source container database (CDB), plug it into a later release target CDB, and then complete all the steps required to upgrade the PDB to the target CDB release.

There are two workflows for unplug-plug PDB upgrades using AutoUpgrade, depending on how you configure the upgrade:

  • You unplug one or more pluggable databases from one source CDB, and plug them into a new release target CDB
  • You unplug multiple pluggable databases from different source CDBs, and plug them into a new release target CDB

After the upgrade, for each PDB, you must configure database listeners and local naming parameters (tnsnames.ora files). You must also configure Oracle Wallet management.


As with any other change to the database, before you run AutoUpgrade to complete the conversion and upgrade, Oracle strongly recommends that you implement a reliable backup strategy to prevent unexpected data loss. There is no option to roll back an unplug-plug PDB upgrade after AutoUpgrade starts this procedure. AutoUpgrade does not support unplug-plug upgrades of PDBs that use Transparent Data Encryption (TDE), or that have an encrypted tablespace.

The following illustration shows the two unplug-plug options you can use:

  1. Unplug PDBs from one source Oracle Database 12.2 CDB (CDB1, with pdba and pdbb) and plug them into a new release target CDB (CDB3).
  2. Unplug PDBs from multiple source CDBs (Oracle Database 12.2 on CDB1, pdba and pdbb), and Oracle Database 18c, CDB2, pdbc and pdbd), and plug them into a new release target CDB (CDB3).

Figure 4-2 Unplug-Plug Upgrades from Source to Target

Description of Figure 4-2 follows
Description of "Figure 4-2 Unplug-Plug Upgrades from Source to Target"

Requirements for Source and Target CDBs

To perform an unplug-plug upgrade, your source and target CDBs must meet the following conditions:

  • You have created the target release CDB, and opened the CDB before starting the unplug-plug upgrade.
  • The endian format of the source and target CDBs are identical.
  • The set of Oracle Database components configured for the target release CDB include all of the components available on the source CDB.
  • The source and target CDBs have compatible character sets and national character sets
  • The source CDB release must be supported for direct upgrade to the target CDB release.
  • External authentication (operating system authentication) is enabled for the source and target CDBs
  • The Oracle Application Express installation type on the source CDBs should match the installation type on the target CDB.
  • There should be no existing guaranteed restore point (GRP) on the non-CDB Oracle Database that you want to plug in to the CDB.


Do not use AutoUpgrade to perform an unplug-plug upgrade to a CDB that is part of an Oracle Data Guard configuration. To upgrade a PDB using an unplug-plug to a CDB with an Oracle Data Guard configuration, you must perform the upgrade manually using the procedure described in the following My Oracle Support note:

Making Use Deferred PDB Recovery and the STANDBYS=NONE Feature with Oracle Multitenant (Doc ID 1916648.1)

Features of Unplug-Plug Upgrades

When you select an unplug-plug upgrade, depending on how you configure the AutoUpgrade configuration file, you can use AutoUpgrade to perform the following options during the upgrade:

  • You can either keep the PDB name that you have in the source CDB, or you can change the PDB name.
  • You can make a copy of the data files to the target CDB, while preserving all of the old files.
  • You can copy the data files to the target location, and then delete the old files on the source CDB
  • You can process one PDB, or you can link to an inclusion list and process many PDBs in one upgrade procedure; the only limit for the number of PDBs you can process are the server limits, and the limits for PDBS on the CDB.

Example 4-3 AutoUpgrade Configuration File for Unplug-Plug Upgrades

To use the unplug-plug PDB upgrade option, you must set the system identifier parameters for the source CDB and PDB, parameter target_cdb in the AutoUpgrade configuration file. The target_cdb parameter value defines the Oracle system identifier (SID) of the container database into which you are plugging the non-CDB Oracle Database. For example:

global.autoupg log_dir=/home/oracle/autoupg