Upgrading to Oracle 12c - Expert Consolidation in Oracle Database 12c - page 414

Chapter 12

Upgrading to Oracle 12c

The final chapter of this topic will deal with the upgrade to Oracle 12c. It is unlikely that your Database as a Service
(DBaaS) Platform or consolidation project starts on the green field, but if it does: congratulations! You probably
waited just long enough to get started with the right technology for the task. This chapter, just like the rest of the
book, is written specifically for Pluggable Databases (PDB) and consolidation in mind. However, since PDBs are a
new feature you cannot migrate a database from a previous release straight into a PDB using the traditional upgrade
path described here. There are of course other methods available to transfer your schemas from a pre 12c database
into a PDB.
To convert your complete pre-12c database into a PDB you need to migrate the existing database to a 12c
non-Container Database (CDB) first. In the next step you can use the techniques described in this chapter to convert
the database to a PDB inside an existing CDB. Note that you need to be on the same platform for this to
work-converting databases from one platform to another is a different problem.
Although the migration from a previous version to the current release using the DB Upgrade Assistant or
manual approach seems the most applicable use case, you can also use the Data Pump utilities expdp and impdp to
migrate databases or subsets of the database as well. Other means of transportation include the use of Transportable
Tablespaces or replication technologies. This chapter gives you an overview about migrating from Oracle 11g Release
2 to Oracle 12c Release 1.Oracle 11g Release 2 is the only non 12c release at the time of writing which enjoyed
premium support from Oracle and hence was the obvious candidate to be covered in this chapter.

The upgrade path to Oracle database 12c
As with previous Oracle releases you need to pay close attention to the upgrade prerequisites. One of the most
important prerequisites, supported database versions, is found in the list of database releases supporting a direct
upgrade. The distinction is important since the upgrade options for Oracle Restart are slightly different and will be
covered in a later section in this chapter. The minimum database releases for a direct upgrade are listed in Figure 12-1
shown below.

Figure 12-1. Supported releases for a direct upgrade