The HP Oracle Exadata Storage Server is a storage product highly optimized for use with the Oracle database. Exadata is a combination of software and hardware used to store and access the Oracle database. It provides database aware storage services, such as the ability to offload database processing from the database server to storage, and provides this while being transparent to SQL processing and your database applications. Exadata delivers outstanding I/O and SQL processing performance for data warehousing applications by leveraging a massively parallel architecture to enable a dynamic storage grid for Oracle Database 11g deployments.
Traditional storage products provide the Oracle database a narrow and limited interface to database storage. Many bottlenecks exist today in the database I/O path restricting data bandwidth, and hence limiting overall database performance. Database servers need many Storage Area Network (SAN) Host Bus Adapters (HBA) to provide the bandwidth necessary to deliver data, from storage to the database, at an adequate rate.
The Oracle Database 11g has been significantly enhanced to take advantage of Exadata storage. The Exadata software is optimally divided between the database server and Exadata cell. The database server and Exadata Storage Server Software communicate using the iDB – the Intelligent Database protocol. iDB is implemented in the database kernel and transparently maps database operations to Exadata-enhanced operations. iDB implements a function shipping architecture in addition to the traditional data block shipping provided by the database. iDB is used to ship SQL operations down to the Exadata cells for execution and to return query result sets to the database kernel.
Exadata also has been integrated with the Oracle Enterprise Manager (EM) Grid Control to easily monitor the Exadata environment. By installing an Exadata plug-in to the existing EM system, statistics and activity on the Exadata Storage Server can be monitored and events and alerts can be sent to the administrator. The advantages of integrating the EM system with Exadata include:
Exadata works with Enterprise Manager to provide a graphic user interface to monitor and the Exadata environment.
• Monitoring Oracle Exadata storage
• Gathering storage configuration and performance information
• Raising alerts and warnings based on thresholds set
• Providing rich out-of-box metrics and reports based on historical data
With traditional, non-iDB aware storage, all database intelligence resides in the database software on the server. To illustrate how SQL processing is performed in this architecture an example of a table scan is shown below.