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Overview Oracle's two major index types are Bitmap indexes and B-Tree indexes. B-Tree indexes are the regular type that OLTP systems make much use of, and bitmap indexes are a highly compressed inde...

    The Secrets of Oracle Bitmap Indexes Overview Oracle's two major index types are Bitmap indexes and B-Tree indexes. B-Tree indexes are the regular type that OLTP syste...

Oracle中试图对一个子查询进行更新时可能会出现ORA-01779错误。该错误的内容为：ORA-01779: cannot modify a column which maps to a non-key-preserved table例如，使用以下的更新查询就会出现该错误。CREATE TABL...

SQLPLUS> clear screenSQLPLUS> set timing on

Where exists (subquery)The WHERE EXISTS subquery is used when we want to display all rows where we have a matching column in both tables.  In most cases, this type of subquery can be re-written w...

一、设置初始化参数 job_queue_processes　　sql> alter system set job_queue_processes=n;（n>0）　　job_queue_processes最大值为1000　　　　查看job queue 后台进程　　sql>select name,description from v$bgp...

  1. Enable job queueSQL> alter system enable restrict session;2. make sure oracle has set the job queue parameterin orcl(oracle sid).ora, need to addjob_queue_process = N (proce...

创建job declare    job2 number; begin dbms_job.submit(job2,'test_lk;',sysdate,'sysdate+1'); end; 1创建一个表 create table test_table(a date); 2创建 一个存储过程 create or replace proced...

SQL code --功能概述:删除重复记录 --做成时间:2008/10/31 在几千条记录里,存在着些相同的记录,如何能用SQL语句,删除掉重复的呢?谢谢! 1、查找表中多余的重复记录，重复记录是根据单个字段（peopleId）来判断 select...

9.18号通过了OCP考试接下来复习备份和还原的知识准备准备了你懂的

近日生产库中的一个过程报出了ora-1461的错误，虽然错误实际处理起来非常简单，但解决过程中与yangtingkun老大就该问题思想火花的碰撞还是让我颇有收益。创建一个最简单的示例演示一下错误的触发：SQL> CREATE ...

话说题目是这样的：有三个公司，苹果，微软，IBM。里面自然有好多员工，员工也有月薪。这三个公司每个月要交一定的税。请查询出：这几个公司的每个月要交的税，大于所在员工的最高月薪。并且返回公司名称。举个例子I...

检查系统的硬件需求是否满足RAM > 1GSwap > 1G/tmp > 400MB命令: grep Men(Swap) /proc/meminfo df -m /tmp 以ROOT用户登录 ORACLE数据库安装需要两个用户组：oinstall and dbaORAC...

In 适合于外表大而内表小的情况；Exits 适合于外表小而内表大的情况。in list是非关联子查询，用于子集小的情况下exist是关联子查询，用于母集小的情况下某大型应用数据库系统中，有T1和T2两个表，并且这两个表通过...

set ORACLE_BASE=D:\oracleset ORACLE_SID=orclset ORACLE_HOME=D:\oracleemctl start/stop/status dbconsoleshutdown -abort             &nbsp...

oracle server = instance + databaseinstance = SGA + background processeach server process and background process has one PGAuser process - server process - instancedatabase buff cache: pinned(multiple...