Overview of Oracle databases

There are two main types of Oracle databases.

Single instance: In a single instance Oracle database, only one instance is handling client requests at any time.
Clustered: In an Oracle cluster, there are two or more hardware nodes across which a single database is replicated, allowing access to the same data from any node.

Single instance Oracle database

In this configuration, one node or database server contains a single database and a single instance. The hardware node connects to a SAN or NAS storage device.

Clustered Oracle database

The addition of Oracle RAC or Symantec Veritas Cluster Server (VCS) software adds clustering capability.

Interaction with Automatic Storage Management

Automatic Storage Management (ASM) collects information that is needed to create an ASM Instance.

ASM is available to serve data files to databases on that cluster. Oracle databases are clients to ASM, which is configured in the cluster.

When you create an Oracle cluster or database within BMC Database Automation, you have the option of enabling the use of ASM.

If ASM is enabled during the cluster create process, then ASM is automatically created on nodes that are added to that cluster. When a node is removed, ASM is removed. When a cluster is removed, ASM is removed with that cluster.

Note

For environments running Oracle 11g on Linux, to use ASM within BMC Database Automation, you must first set up ASMLib in the OS and expose the devices that you want to make available within BMC Database Automation. The disks you expose are allocated during the create database process. After you specify which disks should be used for ASM, they are automatically grouped.

When ASM is enabled, it collects information needed to create an ASM instance.

As an alternative to ASM for storing data files and redo logs, BMC Database Automation also supports all clustered file systems supported by Oracle.

Interaction with listeners

You can use BMC Database Automation to provision listeners while creating a new single instance Oracle database and while creating Oracle clusters. Every listener that is created is registered with all database instances running on the local node. A single listener can be used to allow access to all instances running on the local node. There is no requirement for more than one listener for each node, which is the easiest configuration to manage.