今天跟研发的同学讨论到了这个问题,index block split过程中涉及到的重新排序问题.
SQL> create table idx_split (a number, b varchar2(1446), c date); Table created SQ[......]
December 12, 2012 Internals, oracle No comments structure
今天跟研发的同学讨论到了这个问题,index block split过程中涉及到的重新排序问题.
SQL> create table idx_split (a number, b varchar2(1446), c date); Table created SQ[......]
August 17, 2012 Internals, maintain, oracle 2 comments structure
帮朋友check一次中国银联数据库的坏块问题(并不是严格意义上的坏块),大致情况为smon需要trascation recover —>特定的block 发现无法读取 —>transaction recover出现问题 —>smon terminated
Wed Aug 15 19:02[……]
June 7, 2012 Internals, oracle No comments structure
对于BITMAP index的使用 一直存在一些争议 我们来看看下面几个观点：
1. Low cardinality – Some dabase vendor, like Oracle, provides very practical suggestion
If the num[……]
昨天看了roger的一篇文章，如何在创建index 之前估算它的大小，这里有一种更简单的方法实现：
主要思路就是采用了dbms_space.create_index_cost这个包
–create a testing table named t
SQL> create tabl[……]
February 20, 2012 backup, oracle, replication No comments structure
系统alert在主库出现下面错误 OS为linux 5.5
Stopping background process CJQ0
Sat Feb 11 03:41:07 2012
Hex dump of (file 9, block 561424) in trace file /data/[……]
January 16, 2012 linux, system 5 comments structure
Regular Pages and HugePages
This section aims to give a general picture about memory access in virtual memory systems and how pages are referenced.[……]
January 13, 2012 Internals, oracle No comments structure
NOLOGGING is supported in only a subset of the locations that support LOGGING. Only the following operations support the NOLOGGING mode:
DML:
1. Dir[……]
January 8, 2012 maintain, oracle 2 comments structure
收到开发人员报告，oracle出现坏块，信息如下：
Hex dump of (file 7, block 1407500) in trace file /data/oracle/admin/orcl/bdump/orcl_p004_7383.trc
Corrupt block relativ[……]
January 4, 2012 maintain, oracle No comments structure
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：
——————————-[……]
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[……]