1: memory structure(内存结构) memory structure分为两部分: SGA(System Global Area)区是用于存储数据库信息的内存区,该信息为数据库进程所共享。它包含Oracle 服务器的数据和控制信息, 它是在Oracle 服务器所驻留的计算机的实际内存中得以分配,如果实际内存不够再往虚拟内存中写。 包括: .share pool .datafase ...
一般情况下我们以一台机器上安装Oracle时都是以Instance和Database一对一的方式,但是在Oracle集群(Oracle RAC环境)的情况下他是多个Instance对应一个Database。 Oracle Instance有两部分组成: Memory Structures(内存结构):Memory Structures就是Oracle Instance中的SGA。 Background Process Structures(后台进程结构):Backgr...
第一章DBAI第一章ORACLE体系结构这章理论比较多,可能有点枯燥。大伙儿要打起精神。从本章开始我们正式进入DBA I, DBA是一个岗位的缩写database adminstrator,也确实是数据库治理员。要做一个称职的DBA,需要全
Database Management System (DBMS) Adatabase management system (DBMS)is software that controls the storage, organization, and retrieval of data. Typically, a DBMS has the following elements: Kernel code This code manages memory and storage for the DBMS. ...
One or more datafiles form a logical unit of database storage called a tablespace. Data in a datafile is read, as needed, during normal database operation and stored in the memory cache of Oracle. For example, assume that a user wants to access some data in a table of a database. If...
ORACLE由两部分:实例和数据库\x0d\x0a实例由以下组成: SGA,Shared pool,Database buffer cache,Redo log buffer cache.\x0d\x0a数据库由物理文件组成,其中必须有的文件是:数据文件,控制文件,重做日志\x0d\x0a另外还有:参数文件,口令文件,归档日志文件(这三个不是必须的)\x0d\x0aORACLE ...
The SGA is a shared memory structure allocated when the instance started up and released when it is shut down. The SGA is a group of shared memory structures that contain data and control information for one database instance. SGA是在实例启动时分配的共享内存结构,在关闭时释放。 SGA是一组共享...
Oracle Database Feature Comparison with Other Databases Database Feature/FunctionalityOracle DatabaseDB2SQL ServerSybaseInformix Row-level locking Yes Yes (with isolation levels) No Yes No Active-active clustering Yes Yes (DB2 PureScale) No Yes (via Cluster edition) No Integration with in-memory ...
Value Proposition:Oracle Database 12c In-Memory allows administrators to dedicate a certain amount of database server memory to the Column Store – a memory structure that stores data in column format instead of in row format. Setup of the Column Store is fast and easy. Having data available ...
内存结构描述的是Oracle 数据库对内存的使用构成。Oracle 内存结构被总称为SGA (System Global Area),主要包括数据库高速缓冲区(Database Buffer Cache)、重做日 志缓冲区(Redo Log Buffer)和共享池(Shared Pool)三个部分。Oracle 后台进程主要包括DBWn、CKPT、LGWR、SMON、PMON、ARCn 和RECO。