Oracle Parallel Processing

Parallel Processing for Databases

Three issues are driving the increasing use of parallel processing in database environments:

The need for increased speed or performance

Database sizes are increasing, queries are becoming more complex—especially in data warehouse systems—and the database software must somehow cope with the increasing demands that result from this complexity.

The need for scalability

This requirement goes hand-in-hand with performance. Databases often grow rapidly, and companies need a way to easily and cost-effectively scale their systems to match that growth.

The need for high availability

High availability refers to the need to keep a database up and running with minimal or no downtime. With the increasing use of the Internet, companies need to accommodate users at all hours of the day and night.

Speedup

Database sizes have been increasing steadily, and it’s now quite common to find data warehouses holding several hundred gigabytes of data. Some databases, referred to as Very Large Databases (VLDBs), even hold several terabytes of data. Complex queries are run on these data warehouses to gather business intelligence and to aid in decision making. Such queries require a lot of processing time to execute. By executing these queries in parallel, you can reduce the elapsed time while still providing the required processor time.

Speedup is defined as the ratio between the runtime with one processor and the runtime using multiple processors. It measures the performance ...