maintain

分区表中的index 失效及处理

January 4, 2012 maintain, oracle No comments

分区表中 local 索引的维护会在oracle 操作表分区的时候自动进行,需要注意的是global 索引,当global索引所在表执行alter table 涉及下列操作时,会导至该索引失效,需要重新建立:

——————————-[……]

Read more

在线重定义一例

December 29, 2011 maintain, oracle 1 comment

创建需要redefinition的表,结构同源表

— Create table
create table yhd_so_temp
(id NUMBER(18) not null,
end_user_id[……]

Read more

How to create very big index

December 29, 2011 11g, maintain, oracle No comments

how to create very big index

我们总会碰到各种case 需要建立索引 有些索引大至1T,这些索引的创建是个非常棘手的问题,oracle 11g 在建立partition index时,给出了不错的解决方案

Let’s now re-create th[……]

Read more

[转]Local Index Issue With Partitioned PK and Unique Key Constraints

December 27, 2011 maintain, oracle

看到一篇不错的文章 转载下

Nuno Souto (Noons) also asked a really interesting question on my Differences between Unique and Non-Unique Indexes blog entry (c[……]

Read more

BTREE索引浅解

December 22, 2011 maintain, oracle No comments

结构如下图所示:

对于分支节点块(包括根节点块)来说,其所包含的索引条目都是按照顺序排列的(缺省是升序排列,也可以在创建索引时指定为降序排列)。每个索引条目(也可以叫做每条记录)都具有两个字段。第一个字段表示当前该分支节点块下面所链接的索引块中所包含的最小键值;第二个字段为四个字节,表示所[……]

Read more

一次LOB字段的查询导致的系统问题以及sql_id变化的探究

December 20, 2011 maintain, oracle No comments

16号早上10点左右发现系统变慢,查看等待事件 发现大量i/o salve wait, load 比值增加,等待语句sql_id为 38wm92jbxu0vf

09:59:30 up 80 days, 8:00, 2 users, load average: 16.02, 4.[……]

Read more

Limitations of DRIVING_SITE Hint

December 19, 2011 maintain, oracle No comments

Limitations of DRIVING_SITE Hint

Applies to:

Oracle Server – Enterprise Edition – Version: 9.2.0.1 to 11.2.0.2
This problem can occur on a[……]

Read more

ORA-01555 on Active Physical standby and patchset issue without Central Inventory

December 7, 2011 maintain, oracle, replication 2 comments

今天在生产库解决一个ORA-01555 on Active Physical standby问题:
Applies to:

Oracle Server – Enterprise Edition – Version: 11.2.0.2.0 and later [Release: 11.2[……]

Read more

SQL*Loader to load data with virtual column

December 6, 2011 maintain, oracle No comments

在使用sqlldr工具导入数据的时候 往往需要将导入的某列按顺序排列,我们可以使用sqlldr 的虚拟列功能实现

[oracle@liu ~]$ sqlplus ‘/as sysdba’

SQL*Plus: Release 10.2.0.1.0 – Production on Tue[……]

Read more

Reasons that a TX lock may be requested in S mode

December 4, 2011 maintain, oracle 2 comments

Oracle中的锁,一共有6种模式:

0:none
1:null 空
2:Row-S 行共享(RS):共享表锁,sub share
3:Row-X 行独占(RX):用于行的修改,sub exclusive
4:Share 共享锁(S):阻止其他DML操作,share
5:S/Row-[……]

Read more