What is Oracle RAC architecture?

RAC Architecture. Oracle Real Application clusters allows multiple instances to access a single database, the instances will be running on multiple nodes. In an standard Oracle configuration a database can only be mounted by one instance but in a RAC environment many instances can access a single database.

What are the RAC background processes in Oracle?

Background Processes Specific to Oracle RAC

What are Oracle RAC components?

At a very high level, RAC architecture consists of these components:

• Physical Nodes or Hosts.
• Physical Interconnects and interconnect protocols.
• Cluster Manager Software and Cluster Ready Services.
• Oracle Instances and Cache Fusion.
• Shared Disk System.
• Clustered File System, Raw Devices, Automatic Storage Management.

How can I learn Oracle RAC?

Some things to try out are listed below.

1. Create a VM and install the Oracle software.
2. Add several virtual hard drives to a VM.
3. Configure them to be ASM disks.
4. Practice adding and removing disks within ASM.
5. Define failure groups.
6. Practice backup/recovery using ASM.
7. Practice disaster recovery using ASM.

What is the purpose of Oracle RAC?

The main aim of Oracle RAC is to implement a clustered database to provide performance, scalability and resilience & high availability of data at instance level.

What are the benefits of Oracle RAC?

The Benefits of Real Application Clusters

• Lower Overall Cost of Ownership.
• Expanded Scalability.
• High Availability.
• Transparency.
• Buffer Cache Management.
• Row Locking.
• Recovery Manager, Online Backups, and Archiving.

What is GCS and GES in RAC?

Global Cache Service (GCS) and Global Enqueue Service (GES) GCS and GES (which are basically RAC processes) play the key role in implementing Cache Fusion. GCS ensures a single system image of the data even though the data is accessed by multiple instances.

What is OLR and OCR in RAC?

ORACLE LOCAL REGISTRY(OLR) contains node-specific information required by OHASD . Every node has its own dedicated OLR file. (not shared between the nodes). As OCRs files are present in ASM diskgroup, While starting the CRS, it wont be able to Access OCR file to find the cluster resource information.

What is the use of Oracle RAC?

Oracle Real Application Clusters (RAC) allow customers to run a single Oracle Database across multiple servers in order to maximize availability and enable horizontal scalability, while accessing shared storage.

What is Oracle RAC for beginner?

Oracle RAC technology is the advance level of database which is designed to provide high availability and scalability. Oracle RAC is installed on multiple servers and it forms the foundation for database cloud. Build a Strong Foundation in Oracle grid, Clusterware Installation with this book for Beginners.

What is RAC in Oracle 12c?

Oracle Database with the Oracle Real Application Clusters (RAC) option allows multiple instances running on different servers to access the same physical database stored on shared Storage. The database spans multiple hardware systems and yet appears as a single unified database to the application.

What is difference between Oracle and Oracle RAC?

A database may be mounted and opened by many instances, either one after the other or by many simultaneously (that is RAC). In an RAC environment, you run an instance of Oracle on each machine (also known as a node) in the cluster. Each of these instances mount and open the same database, since clusters share disks.