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1、实验安排,地点：信息楼603 网络工程 第2-5，7-16周， 周四1-2节 第11，14周， 周四3-4节 软件工程 第2-5，7-15周， 周四7-8节 第10，13，16周，周四3-4节 兴湘 第2-5，7-16周， 周三3-4节 第12，15周， 周四3-4节,Oracle Architecture and Management,Oracle的发展变迁,1977年Larry Ellison、Bob Miner和Ed Oates共同创建了软件开发实验室 1979年，Oracle的第一个产品被发行。 1985年, Oracle公司推出了版本5，引入了Client/Server计算 1988
2、年，Oracle 6版本，可以运行在多种平台和操作系统上 1998年，Oracle 8i，世界上第一个全面支持Internet的数据库 2001年6月，在Oracle Open World大会中，Oracle发布了Oracle 9i 2003年9月， Oracle 10g发布，g(grid) 2007年11月，Oracle 11g正式发布 ， Oracle 11gr2 2013年6月，Oracle 12c正式上市，c(cloud), 64位。,Oracle Architectural Components,Overview of Primary Components,Instance,SGA,
3、Redo logbuffer cache,Shared pool,Data Dict.cache,Library cache,DBWR,SMON,PMON,CKPT,LGWR,Others,Userprocess,Serverprocess,PGA,Control files,Data files,Archived log files,Parameter file,Password file,Redo log files,Database,Databasebuffer cache,Oracle Server,An Oracle server: Is a database management
4、system that provides an open, comprehensive, integrated approach to information management Consists of an Oracle instance and an Oracle database,Oracle Server,Oracle Instance,An Oracle instance: Is a means to access an Oracle database Always opens one and only one database Consists of memory and pro
5、cess structures,Background structures,Memory structures,SGA,Redo logbuffer cache,Database buffer cache,Shared pool,DBWR,SMON,PMON,CKPT,LGWR,Others,Data Dictionarycache,Library cache,Instance,Establishing a Connection and Creating a Session,Connecting to an Oracle instance consists of establishing a
6、user connection and creating a session.,Oracle Database,An Oracle database: Is a collection of data that is treated as a unit Consists of three file types,Control files,Data files,Archived log files,Parameter file,Password file,Redo log files,Oracle Database,Physical Structure,The physical structure
7、 of an Oracle database is determined by the operating system files that provide the actual physical storage for database information. Control files Data files Redo log files,Memory Structure,Oracles memory structure consists of two memory areas known as: System Global Area (SGA): Allocated at instan
8、ce startup, and is a fundamental component of an Oracle Instance Program Global Area (PGA): Allocated when the server process is started,System Global Area (SGA),The SGA consists of several memory structures: Shared pool Database buffer cache Redo log buffer Other structures (e.g. lock and latch man
9、agement, statistical data) There are two optional memory structures that can be configured within the SGA: Large pool Java pool,System Global Area (SGA),SGA is dynamic and sized using SGA_MAX_SIZE. SGA memory allocated and tracked in granules by SGA components Contiguous virtual memory allocation Si
10、ze based on SGA_MAX_SIZE,Shared Pool,The shared pool is used to store the most recently executed SQL statements and the most recently used data definitions. It consists of two key performance-related memory structures: Library cache Data dictionary cache Sized by the parameter SHARED_POOL_SIZE.,ALTE
11、R SYSTEM SET SHARED_POOL_SIZE = 64M;,Library Cache,The library cache stores information about the most recently used SQL and PL/SQL statements. The library cache: Enables the sharing of commonly used statements Is managed by a least recently used (LRU) algorithm Consists of two structures: Shared SQ
12、L area Shared PL/SQL area Has its size determined by the shared pool sizing,Data Dictionary Cache,The data dictionary cache is a collection of the most recently used definitions in the database. It includes information about database files, tables, indexes, columns, users, privileges, and other data
13、base objects. During the parse phase, the server process looks at the data dictionary for information to resolve object names and validate access. Caching the data dictionary information into memory improves response time on queries. Size is determined by the shared pool sizing.,Database Buffer Cach
14、e,The database buffer cache stores copies of data blocks that have been retrieved from the data files. It enables great performance gains when you obtain and update data. It is managed through a least recently used (LRU) algorithm. DB_BLOCK_SIZE determines the primary block size.,Database buffercach
15、e,Redo Log Buffer Cache,The redo log buffer cache records all changes made to the database data blocks. Its primary purpose is recovery. Changes recorded within are called redo entries. Redo entries contain information to reconstruct or redo changes. Size is defined by LOG_BUFFER.,Redo logbuffer cac
16、he,Userprocess,Program Global Area (PGA),The PGA is memory reserved for each user process that connects to an Oracle database.,Stack space,Session information sort area, cursor information,SGA,Shared SQL areas,SGA,PGA Dedicated server Shared server,Serverprocess,Shared SQL areas,Stack space,sort area, cursor information,Process Structure,An Oracle process is a program that depending on its type can request information, execute a series of steps, or perform a specific task. Oracle takes advantage
