Slow is smooth , Smooth is fast ! ( 点滴回忆 )

1. 起别名时,使用到特殊符号,例如 # , 要加双引号 " "    SELECT WORK_DATE "#"    FROM   ZHPPEXP05    WHERE  WORK_DATE = '20080104'2.DISTINCT 关键字要放在查询的第一个     SELECT DISTINCT WORK_DATE ,                     S

1.Control file 作用( small binary file , defines the current state of the physical database , server 自动修改,不能手动修改 )2进制文件 small 几十 MB没有control file 必须恢复数据库到有control file时在mount状态下读取( 跟之前的开启数据库是相关的

1.Data DictionaryDuring database creation , the Oracle server creates additional object structureswithin the data files.当数据库创建时, 就会自动在 data files 中创建一些其他结构. （安装完数据库后要安装的脚本)Data dictionary tabl

1.创建数据库之前的准备工作a privileged (SYSDBA) account authenticated in one of the following ways : ( By the operating system | Using a password file )Sufficient memory to start the instance and sufficient d

1. Initialization parameter file ( pfile , spfile )To start an instance, the Oracle server must read the initialization parameter file . ( 在打开数据库时, 必须读取此参数文件 )explicit / implicitexplicit : hav

1. OFA ( Optimal Flexible Architecture )     OFA ivoloved 3 rules :       - Establish a directory structure where any database file can be stored on any disk resource        // 建立目录结构, 使得数据库文件可以

1. server process :  when a user logs on to the oracle server , a process is created on the computer running the oracle server . ( 输入完用户名密码 ) (dedicated / shared )2. session : A session is a spe

ObjectivesAfter completing this lesson, you should be able to do the following :Describe the logical structure of the databaseList the segment types and their usesList the keywords that control

ObjectivesAter completing this lession, you should be able to do the following :descibe the logical structure of the databasecreate tablespaceschange the size of tablespacesallocate space for te

1.subquery  You can place the subquery in a number of SQL clauses , including :    The WHERE clause , The FROM clause , the HAVING clause .  SELECT job_id,AVG( salary )  FROM employees  GROUP

1. Datetime Function ( 前面有相关内容 )    The hours of the day are measured by the turning of the earth . The time of day at any particular moment depends on where you are.  时区介绍 : 全球共分为24个时区 , 每个时区占经

1. Constraints    NOT NULL , UNIQUE , PRIMARY KEY , FOREIGN KEY , CHECK ( 单行约束的 NOT NULL , 一顶要放到单行的最后位置 )         CREATE TABLE employees (                                                       -

1. PL/SQL 好处  Integration : 集成度高 ( server 和 application 中都有 , 例如 : Oracle Developer )  Improved performance : ( 必须系统中计算工时 , 如果使用 procedure , 则只需要传几个参数过去 , 可以很少的使用 network ,

用法sqlplus需要设置环境变量oracle_home 环境变量oracle_sid( 只是针对安装的server需要此环境变量，客户端登录sqlplus时不需要此环境变量)path 特别是 oracle_home/bin 执行目录，只有设置了这个环境变量才能在任何位置执行sqlplustns_admin(tnsnames.ora) 我们自己系统设置此内容，只有设置此内容才准

1.再谈触发器 ( 以下内容为摘抄 )8.1 触发器类型8.1.1 DML触发器8.1.2 替代触发器8.1.3 系统触发器8.2 创建触发器8.2.1 触发器触发次序8.2.2 创建DML触发器8.2.3 创建替代(INSTEAD OF)触发器8.2.3 创建系统事件触发器8.2.4 系统触发器事件属性8.2.5 使用触

1. CREATE PACKAGE ( PACKAGE 有问题, 没搞懂 )  Packages bundle related PL/SQL types, items, and subprograms into one container.  A package usually has a specification and a body, stored separately in t

1. Exception  种类 : Predefine Oracle Server                       ( Implicitly raised ) , 只有20个             NonPredefine Oracle Server                ( Implicitly raised )  除了以上20个,其他server提供的exc

1.INSERT语句一次插入多行( 包括复杂情况 )  INSERT [ ALL ] [ conditional_insert_clause ]  [ insert_into_clause values_clause ] ( subquery )  conditional_insert_clause     [ ALL ] [ FIRST ]    [ WHEN con

ObjectAfter complete this lesson, you should be able to do the following :Explain the purpose of online redo log filesOutline the structure of online redo log filesControl log switches and check