Oracle 12c database creation using DBCA

Oracle 12c database creation using DBCA

Multitenant Architecture for Database Consolidation

Container databases are part of the 12c new feature called Multitenant Architecture.

The concept is that you have a Container database (CDB) at the root or top level which is in turn comprised of a number of pluggable databases (PDB).

Simplistically put, the CDB has the Oracle-supplied metadata like the Data Dictionary which is common to all the PDB’s in that Container database and each individual PDB contains the application data. We have the concept of common users which are common to all PDB’s in the CDB and each PDB can have its own distinct and individual users.

The rationale behind the muiltitenant architecture introduced in 12c is that instead of having hundreds of servers hosting hundreds of databases usually on different platforms and where in most cases the resources on each server are not fully utilized, go for database consolidation with the Container Database topology.

This hardware consolidation and sharing of the database background processes, memory, files etc reduce costs for hardware, storage, availability, as well as the administrative labor cost.

Administrative tasks like patch application and database upgrades are significantly less costly to the business and time consuming for the DBA’s because the patch or upgrade happens at the container level and not the individual database level.

Enterprise Manager Database Express

Enterprise Manager Database Control is no longer available in Oracle Database 12c. It has been replaced by Oracle Enterprise Manager Database Express.

It is scaled down version of Database Control and is an extremely light weight web-based tool for performing basic administration tasks and performance management. There is now a consolidation of several of the performance screens seen in the previous Database Control into what is referred to now as the database Performance Hub.

If we select the Advanced Mode in the Creation Mode screen, we will see the screens as shown below:


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12c Release 1 database software installation on Linux

Here is a quick look at the installation of the 12c database software on an Oracle virtual machine running Oracle Enterprise Linux 5.8

Most of the screens in the installation are very similar to 11g R2, and I have pointed out some of the new things we will see when we do the 12c install.

If we select the option to create and configure a database instead then we are presented with a new screen

The System Class screen gives us the option of Desktop or Server class.

If we select the Desktop class, it is appropriate if we are doing a test install on a PC desktop or laptop and a number of deployment options like ASM, RAC, backup and recovery configuration, integration with OEM Cloud Control etc are not available in this option.

Some new groups have been added to the standard OSDBA and OSOPER groups which we had in earlier versions.

For example the OSDGDBA group is if we want to have a separate group of OS users for administering or monitoring databases in the Oracle Data Guard configuration or the group OSKMDBA group which relates to privileges around encryption key management like Oracle Wallet Manager.