oracle后臺操作手册.doc

1、DDL(Data Definition Language) Command create,alter,drop objects; grant,revoke privileges and roles; establishing auditing options; add comments to the data dictionary; Before and after each DDL statement,Oracle implicitly commit the current transactions. 2、DML(Data Manipulation Language) Command Query and Modify data within existing schema objects; DML statements consist of DELETE,INSERT,SELECT and UPDATE statements; EXPLAIN PLAN statements; LOCK TABLE statements; Unlike DDL Command , a commit is not implicit , after execute DDL Command ,must execute commit command to commit a transaction; 3、Dynamic Performance Tables These tables are created at the instance startup and used to store information about the performance of the instance. This information includes connection informatioion,I/OS, initialization parameter values and so on.. 4、Procedure and Function are identical except that Founction are always return a value(Procedure do not). 5、Schema is a collection of Objects that associated with the DataBase. 6、SGA is made up of : DataBase Buffers; Redo Log Buffers; The Shared Pool; 7、Transaction is a logical unit of work consisting of one or more SQL statements,ending in a commit or rollback. 8、 The DataBase The Physical Layer （1）One or more datafiles; （2）Two or more redo log files; （3）One or more control files; The Logical Layer （1）One or more tablespaces; （2）The database schema; 9、The database is devided into one or more logical pieces known as tablespace; 10、Recommend that every one need DBA roles should have a different account , thus , if auditing is enabled , there is a record who made these system changes. 11、The Instance is the logical term that refers to the components necessary to access the data in a database. 12、数据库实例（也称为服务器Server），是用来访问一个数据库文件集的一个存储结构及后台进程的集合。Oralce并行服务器是指一个单独的数据库可以被多个实例访问。 13、查询实例名： select instance_name from v$instance； 14、查询动态视图v$waitstat、v$system_event、v$session_event、