1.3 Oracle Exadata Database Machine Performance Features

Oracle Exadata Database Machine not only provides high performance and scalability but also unique technology.

The Exadata database servers can offload data-intensive SQL operations to Oracle Exadata Storage Servers. Moving the SQL processing to Oracle Exadata Storage Servers enables data filtering and processing to occur immediately and in parallel across all storage servers as data is read from disk. Exadata storage offload reduces database server CPU consumption and greatly reduces the amount of data moved between the storage and database servers.

Compressing data can provide a dramatic reduction in the storage consumed for large databases. Oracle Exadata Storage Server provides a very advanced compression capability called Hybrid Columnar Compression. Hybrid Columnar Compression enables the highest levels of data compression and provides tremendous cost savings and performance improvements due to reduced I/O. On conventional systems, enabling high data compression has the drawback of reducing performance. Oracle Exadata Database Machine is able to offload decompression overhead into a large number of processors in Oracle Exadata Storage Servers so most workloads run faster using Hybrid Columnar Compression than they do without it. Hybrid Columnar Compression combines the compression and analytic performance benefits of column storage while avoiding the dramatic slowdown that pure columnar stores experience for drill-down operations.

Oracle Exadata Database Machine uses the latest PCIe flash technology rather than flash disks. PCIe flash greatly accelerates performance by placing flash directly on the high speed PCIe bus rather than behind slow disk controllers and directors. Refer to Hardware Components of Oracle Exadata for information about flash card configurations and capacity.

Exadata Smart Flash Cache automatically caches frequently accessed data in PCIe flash while keeping infrequently accessed data on disk drives. This provides the performance of flash with the capacity and cost of disk. Exadata Smart Flash Cache understands database workloads and when to avoid caching data that will never be reused or fit in the cache. Oracle Database and Oracle Exadata System Software allow the user to provide directives at the database table, index and segment level to ensure that specific data is retained in flash. Tables can be retained in flash without the need to move the table to different tablespaces, files or LUNs as would have to be done with traditional storage and flash disks.

Note:

Oracle Exadata Database Machine does not include any Oracle software licenses. Appropriate licensing of the following software is required when Oracle Exadata Database Machinee is used as a database server:

• Oracle Database

• Oracle Exadata System Software

In addition, Oracle recommends that the following software is licensed:

• Oracle RAC

• Oracle Partitioning