Oracle Exadata Database Machine is engineered to be the highest performing and most available platform for running Oracle Database.
Oracle Exadata Database Machine and Oracle Exadata Storage Expansion Rack are hardware systems that consist of multiple components. This chapter provides an overview of Exadata systems, and usage information.
Oracle Exadata Database Machine is a modern architecture featuring scale-out industry-standard database servers, scale-out intelligent storage servers, and an extremely high speed internal RDMA Network Fabric that connects the database and storage servers.
Oracle Exadata Database Machine runs all types of database workloads including Online Transaction Processing (OLTP), Data Warehousing, and a consolidation of mixed workloads. Oracle Exadata Database Machine powers and protects the most important databases, and is the ideal foundation for a consolidated database cloud.
Oracle Exadata Database Machine includes all the hardware needed to run Oracle Database. The database servers, storage servers and network are preconfigured, pretuned and pretested by Oracle engineers, eliminating the weeks of effort typically required to deploy a high performance system. Extensive end-to-end testing ensures all components work together and there are no performance bottlenecks or single points of failure that can affect the complete system. Oracle Exadata Database Machine also includes the Oracle Exadata System Software, which runs on both database servers and storage servers. Unique software algorithms in Oracle Exadata System Software implement database intelligence in storage, PCI-based flash, and the RDMA Network Fabric network to deliver higher performance and high capacity at lower costs than other platforms.
Oracle Exadata Database Machine Configurations
Oracle Exadata Database Machine can come in a specific configuration, for example the half rack, or use an elastic configuration with a custom number of database servers and storage servers.
Oracle Exadata Database Machine uses a scale-out architecture for both database servers and storage servers. As Oracle Exadata Database Machine grows, more database CPUs, storage and networking are added in a balanced fashion, ensuring scalability without bottlenecks. The first Oracle Exadata Database Machine models (X2 and X3) had fixed configurations, such as the half rack or the quarter rack.
Now you can upgrade Oracle Exadata Database Machine to custom configurations called “elastic configurations”. Elastic configurations enable you to build an Oracle Exadata Rack containing a custom number of database servers and storage servers that meet your needs.
In addition to upgrading within a rack, multiple racks can be connected using the integrated RDMA Network Fabric to form larger configurations. For example, a system composed of four Oracle Exadata Full Racks is four times as powerful as a single rack system. The four racks provide quadruple the I/O throughput, storage capacity and processors. It can be configured as a large single system or logically partitioned for consolidation of multiple databases. Oracle Real Application Clusters (Oracle RAC) can dynamically add more processing power, and Oracle Automatic Storage Management (Oracle ASM) can dynamically add more storage.
When larger storage capacity is required Oracle Exadata Storage Expansion Rack is available. Oracle Exadata Storage Expansion Rack enables growth of storage capacity and bandwidth for any Oracle Exadata Database Machine. It is designed for database deployments that require very large amounts of data including historical or archival data, backups, documents, images, XML, large objects (LOBs), and so on. Oracle Exadata Storage Expansion Rack starts with the quarter rack size, and you can add as many additional storage servers as you need. The servers in the Oracle Exadata Storage Expansion Rack connect to Oracle Exadata Database Machine using the integrated RDMA Network Fabric. Configuration does not require set up of logical unit numbers (LUNs) or mount points. Storage is configured and added to the database online using a command line interface.
All Oracle Exadata Database Machines are configured identically so customers benefit from the experience of other users who have deployed Oracle Exadata Database Machine for their mission-critical applications.
Oracle Exadata Database Machine runs standard Oracle Database. Any applications that run with Oracle Database can be seamlessly migrated to Oracle Exadata Database Machine with no changes to the application.
Elastic configurations allow Oracle Exadata Racks to have customer-defined combinations of database servers and Exadata Storage Servers. For example, Oracle Exadata Database Machine X5-2 Elastic Configuration elastic configuration can have 0 to 22 database servers, 0 to 19 Exadata Storage Servers, or a combination of database servers and Exadata Storage Servers.
To build an Oracle Exadata system with a custom number of database and storage servers, use Oracle Exadata Configuration Assistant (OECA). OECA is available on Oracle Technology Network:
OECA simplifies the elastic configuration process. OECA facilitates scoping and analyzing elastic configurations and reporting environmental specifications.
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.
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.
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