Database Reference
In-Depth Information
Post-conversion, when you verify the database configuration details, you will notice a change in the services type
as “
Database is policy managed
,” instead of “
Database is admin managed
.” Additionally, you will also observe a
change, an additional underscore
(_)
symbol before the instance number, in the instance name in contrast to the
previous name.
You also need to run through a set of changes in your environment when the database is managed with OEM
Cloud Control 12c containing database services to reflect the change.
5.
Since there is a modification in the instance name, you need to rename the existing
password file of the database to reflect the new names. Go to the $ORACLE_HOME/dbs
directory and use the following example to rename the file:
$ mv orapwDBNAME1 orapwDBNAME_1
6.
If the database was registered with OEM Cloud Control 12c, you must change the existing
instance name with the new instance name.
7.
All admin-managed RAC database-related services are configured defining the
PREFERRED
and
AVAILABLE
options, whereas, for policy-managed databases, a service is defined to
a database server pool, defining either
SINGLETON
or
UNIFORM
options. When a service is
configured to
UNIFORM
option, it will be set to all instance, whereas the
SINGLETON
option will
be set to a single instance. Use the following example to modify an existing database service:
$ srvctl modify service -d
dbname
-s
service_name
-serverpool
srvpl_pdb
-cardinality
UNIFORM|SINGLETON
■
We strongly recommend using the SCan ips to connect to the database to avoid connection issues when a
database is moved between the nodes defined in the server pool.
Note
Instance Caging
When multiple instances are consolidated in a RAC DB node, resource distribution, consumption, and management
become a challenge for a DBA/DMA. Each instance typically will have different requirements and behavior during
peak and non-peak business timeframes. There is a high probability that a CPU thirsty instance could impact the
performance of other instances configured on the same node. As a powerful new feature with Oracle 11gR2,
with
instance caging,
DBAs can significantly simplify and control an instance CPUs/cores overall usage by restricting
each instance to a certain number of CPUs. Large-scale RAC environments can greatly benefit with this option.
Deploying Instance Caging
Instance caging can be deployed by setting two database initialization parameters: the
cpu_count
and the resource
manager on the instance. The following procedure explains the practical steps required to enable instance caging on
the instance:
SQL> ALTER SYSTEM SET CPU_COUNT=2 SCOPE=BOTH SID='
INSTANCE_NAME
';
SQL> ALTER SYSTEM SET RESOURCE_MANAGER_PLAN = default_plan|myplan SCOPE=BOTH SID='
INSTANCE_NAME
';
The first SQL statement restricts the database instance's CPU resource consumption to 2, irrespective of the
number of CPUs present on the local node; the instance CPU resource use will be limited to a maximum of 2 CPU
