Upgrading to Oracle 12c - Expert Consolidation in Oracle Database 12c - page 427

Running the pre-upgrade tool
Beginning with Oracle 12c the name of the pre-upgrade tool has changed to preupgrd.sql . It performs the necessary
pre-upgrade checks. The Database Upgrade Assistant DBUA performs exactly the same checks by the way and invokes
the script as well. The database to be migrated in this chapter has started its life as a “custom” database created with the
Database Configuration Assistant dbca in version 11.2.0.3. It has a standard set of options registered in the server registry:
COMP_NAME VERSION
---------------------------------------- ------------------------------
Oracle XML Database 11.2.0.3.0
Oracle Expression Filter 11.2.0.3.0
Oracle Rules Manager 11.2.0.3.0
Oracle Workspace Manager 11.2.0.3.0
Oracle Database Catalog Views 11.2.0.3.0
Oracle Database Packages and Types 11.2.0.3.0
JServer JAVA Virtual Machine 11.2.0.3.0
Oracle XDK 11.2.0.3.0
Oracle Database Java Packages 11.2.0.3.0
Translating these to dbca options, only the installation of the Java Virtual Machine (JVM) and XML Database
(XMLDB) options have been selected. The selection of these implicitly triggers the deployment of all those other
components automatically. Note that beginning with Oracle 12.1 the use of XML Database is mandatory and XMLDB
and its repository has to be present.
Following the example the file preupgrd.sql and the dependent script utluppkg.sql have been copied
from the new Oracle 12.1 home to a temporary location and executed against the database ora11 running from
the 11.2.0.3 Oracle Home. The script creates a log file and pre-/post upgrade “fixup” scripts. If an ORACLE_BASE
was present-which should be the case with version 11.1 and later installations-then these files are in
$ORACLE_BASE/cfgtoollogs/${ORACLE_SID}/ . The resulting log file is broken down into various sections containing
information about specific parts of the database to be upgraded.
Database information : Including vital information such as the database release, setting of
the compatible parameter as well as the timezone file version.
Renamed Parameters : This section will highlight parameters which have been renamed in
the new Oracle version.
Obsolete/deprecated parameters : This section does not require an explanation. To avoid
warnings when the Oracle database starts with such a parameter you should consider
updating the initialization file.
Component List : This section lists the components installed in the database. This output
is very similar to what you saw earlier in this section. You should investigate why a
component is invalid before upgrading.
Tablespaces : Checks for sufficient space in the Oracle tablespaces SYSTEM, SYSAUX,
UNDO, TEMP. A recommendation is offered to increase the size of these if they are too
small for the migration.
• PreUpgrade Checks : Any potential problems which could arise with the migration are listed
here. There is usually a description plus a solution offered. You should review the proposed
change and act on them if needed.
• PreUpgrade Recommendations : Oracle will most likely recommend gathering of dictionary
statistics.