Expert Oracle Exadata - Parent Directory

CHAPTER 1 WHAT IS EXADATA?reducing the number of servers, and reduce software and maintenance fees. This is a valid way to viewExadata. Because of the combination of features incorporated in Exadata, it is capable of adequatelysupporting multiple workload profiles at the same time. Although it is not the perfect OLTP Machine, theFlash Cache feature provides a mechanism for ensuring low latency for OLTP-oriented workloads. TheSmart Scan optimizations provide exceptional performance for high-throughput, DW-orientedworkloads. Resource Management options built into the platform provide the ability for these somewhatconflicting requirements to be satisfied on the same platform. In fact, one of the biggest upsides to thisability is the possibility of totally eliminating a huge amount of work that is currently performed in manyshops to move data from an OLTP system to a DW system so that long-running queries do not negativelyaffect the latency-sensitive workload. In many shops, simply moving data from one platform to anotherconsumes more resources than any other operation. Exadata’s capabilities in this regard may make thisprocess unnecessary in many cases.Configuration OptionsSince Exadata is delivered as a preconfigured, integrated system, there are very few options available. Asof this writing there are four versions available. They are grouped into two major categories withdifferent model names (the X2-2 and the X2-8). The storage tiers and networking components for thetwo models are identical. The database tiers, however, are different.Exadata Database Machine X2-2The X2-2 comes in three flavors: quarter rack, half rack, and full rack. The system is built to beupgradeable, so you can upgrade later from a quarter rack to half rack, for example. Here is what youneed to know about the different options:Quarter Rack: The X2-2 Quarter Rack comes with two database servers andthree storage servers. The high-capacity version provides roughly 33TB ofusable disk space if it is configured for normal redundancy. The highperformanceversion provides roughly one third of that or about 10TB of usablespace, again if configured for normal redundancy.Half Rack: The X2-2 Half Rack comes with four database servers and sevenstorage servers. The high-capacity version provides roughly 77TB of usable diskspace if it is configured for normal redundancy. The high-performance versionprovides roughly 23TB of usable space if configured for normal redundancy.Full Rack: The X2-2 Quarter Rack comes with eight database servers andfourteen storage servers. The high-capacity version provides roughly 154TB ofusable disk space if it is configured for normal redundancy. The highperformance version provides about 47TB of usable space if configured fornormal redundancy.7