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Chapter 2. Database Processing. Chapter 2. Hardware Configuration and Considerations. Hmmm... Stand-alone configuration, use disk arrays, multiple databases, networked hosts?. Oracle Architecture. Some consideration for configuration. Auguste Rodin - The Thinker (1840 - 1917). Chapter 2.
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Chapter 2 Database Processing Chapter 2 Hardware Configuration and Considerations
Hmmm... Stand-alone configuration, use disk arrays, multiple databases, networked hosts? Oracle Architecture Some consideration for configuration Auguste Rodin - The Thinker (1840 - 1917)
Chapter 2 Stand-alone host • The configuration in our lab Single Host SGA (Server) Background Processes Database Files (Database) Single, local disk drive Page 12
Chapter 2 Stand-alone host • Data files spread across multiple disks Single Host SGA (Server) Background Processes Data Files 01 Data Files 02 Data Files 03 (Database) Disk 0 Disk 1 Disk 2 Page 12
Chapter 2 Stand-alone host Single Host • Shadowed/mirrored data files SGA (Server) Background Processes Data Files 01 Data Files 02 Data Files 03 Each file is mirrored (Database) Disk 0 Disk 1 Disk 2 Data Files 01 Data Files 02 Data Files 03 Page 12 Disk 3 Disk 4 Disk 5
Chapter 2 Stand-alone host Single Host • Shadowed/mirrored data files • What is this configuration called? • RAID 1 • Advantages? • Backup and performance • But shouldn’t it take twice as long to perform each write? That is, isn’t the “write penalty” 100% • No, writes are issued in parallel SGA (Server) Background Processes Data Files 01 Data Files 02 Data Files 03 (Database) Disk 0 Disk 1 Disk 2 Data Files 01 Data Files 02 Data Files 03 Page 12 Disk 3 Disk 4 Disk 5
Chapter 2 Stand-alone host Single Host • RAID 5 SGA (Server) Background Processes Block 0 Block 2 Parity Block 3 Parity Block 4 (Database) Parity Block 5 Block 6 Block 7 Parity Block 8 Page 12 Disk 0 Disk 1 Disk 2
Chapter 2 Stand-alone host Single Host • RAID 5 • Blocks of data file are “striped” across multiple disks • What is parity for? • The parity information is a derived “check value” that enables the values in a failed disk to be reconstructed. • If drive 2 fails, the parity information on drives 0 and 3 would be used to recalculate the values (degraded mode). SGA (Server) Background Processes Block 0 Block 2 Parity Block 3 Parity Block 4 (Database) Parity Block 5 Block 6 Block 7 Parity Block 8 Page 12 Disk 0 Disk 1 Disk 2
Chapter 2 Stand-alone host • A stand-alone host can support multiple databases • Oracle 8i has configuration assistant • Not sure about Oracle 8
Chapter 2 Stand-alone host Single Host
Chapter 2 Stand-alone host Two databases mounted Two instances
Chapter 2 Networked Hosts • The world is not “stand-alone” • A review of high-level networking trends...
Chapter 2 Mainframes Centralized Hard-wired terminals initially Emulated hard-wired terminal image source: Oracle8 Certified Professional DBA Certification Exam Guide
Chapter 2 Client/Server Decentralized Issues: software distribution scalability platform dependence PCs, GUIs, and Ethernet technology image source: Oracle8 Certified Professional DBA Certification Exam Guide
Chapter 2 Internet Centralized Multi-tier architectures image source: Oracle8 Certified Professional DBA Certification Exam Guide
Chapter 2 Networked Hosts • The database server is one of those tiers • Net8 uses Oracle’s Transparent Substrate (TNS) protocol • Allows for remote queries and updates • We’ll cover it in detail in Chapter 13
Chapter 2 Networked Hosts • Oracle vs. SQL Server http://www.microsoft.com/sql/techinfo/deployment/2000/MigrateOracle.asp