ORACLE 9i-23ai – Page 41

Logon Storm and Memory shortage issue ORA-07445 dbgtrReserveSpace (记录一次登录风暴致内存不足的问题)

2013-10-312013-10-21 by weejar zhang

Exception [type: SIGSEGV, Address not mapped to object] [ADDR:0x10] [PC:0x938E8C5, dbgtrReserveSpace()+99] [flags: 0x0, count: 1]
Errors in file /oracle/diag/rdbms/ora11g/ora11g/trace/ora11g_ora_13864.trc (incident=60801):
ORA-07445: exception encountered: core dump [dbgtrReserveSpace()+99] [SIGSEGV] [ADDR:0x10] [PC:0x938E8C5] [Address not mapped to object] []
Incident details in: /oracle/diag/rdbms/ora11g/ora11g/incident/incdir_60801/ora11g_ora_13864_i60801.trc
Use ADRCI or Support Workbench to package the incident.

scn format (scn格式)

2013-10-312013-10-16 by weejar zhang

scn(system change number) 结构主要维护 oracle数据库内部的数据一致性，SCN 有两部分组成: Base and wrap，wrap 是16bit的数字，base是32bit的数字,这样其实就可以算scn的有效范围，它的格式(redo dump trace)是wrap.base，当base超过了2的32次方,然后wrap 就会加1，其实用sql 很好验证。

SQL Test Case Builder generate test case automatically(自动生成SQL所需测试数据)

2013-10-15 by weejar zhang

Why SQL Test Case Builder? For most SQL problems, the single most important factor for a speedy bug resolution is to obtain a reproducible test case. However, this is normally the longest and most painful step for customers. The goal of the SQL Test Case Builder (TCB) is to automatically gather as much information as … Read more

ORA-00313,ORA-00312,ORA-27037,ORA-19527 DATAGARD 11G r2

2013-10-12 by weejar zhang

Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
DDE: Problem Key ‘ORA 312’ was flood controlled (0x5) (no incident)
ORA-00312: online log 2 thread 1: ‘/oracle/oradata/icme/redo02.log’
Error 19527 creating/clearing online redo logfile 2

Send email using utl_smtp in Oracle 11g (results in ORA-24247)(11g ACL 网络访问控制列表)

2013-09-29 by weejar zhang

ORA-24247: network access denied by access control list (ACL)
ORA-06512: at “SYS.UTL_TCP”, line 17
ORA-06512: at “SYS.UTL_TCP”, line 267

Oradebug Security

2014-11-042013-09-25 by weejar zhang

DEMO 1,How to use oradebug to call OS commands via the database
DEMO 2,Disable sys audit

How to imp job to another schema in same db(同一数据库导入JOB到另外一用户)

2013-09-25 by weejar zhang

ORA-39083: Object type JOB failed to create with error:
ORA-00001: unique constraint (SYS.I_JOB_JOB) violated

Dynamically Changing shared_pool_size fail!(动态修改Shared pool size失败)

2013-09-10 by weejar zhang

因安装数据库时启用了ASMM,过了几天发现分配不太理想想禁用ASMM，手动调整shared_pool_size, 这是一个动态参数，修改后立即生效无需重启数据库实例，但修改时遇到了比较奇怪的现象。

ORA-07445 [kggchk()+77] [SIGSEGV] [Address not mapped to object]

2013-08-15 by weejar zhang

今天有个项目系统负载突然变大，查到top sql是一个存储过程,执行计划缺少合理的索引，SQL是个update操作，于是kill 调用的几个session 建立一个索引，结果发现kill几个用户进程后实例挂了.下面是alert日志，可见instance crash前出现过死锁,就是那个update sql Thu Aug 15 11:08:04 2013 ORA-00060: Deadlock detected. More info in file /oracle/admin/icme/udump/icme_ora_24011.trc. Thu Aug 15 11:27:00 2013 ORA-00060: Deadlock detected. More info in file /oracle/admin/icme/udump/icme_ora_26527.trc. Thu Aug 15 11:27:03 2013 ORA-00060: Deadlock detected. More info in file /oracle/admin/icme/udump/icme_ora_26912.trc. Thu Aug 15 11:32:46 2013 ORA-00060: Deadlock detected. More info … Read more

Enabling Listener Trace ,TNS-01251

2013-08-15 by weejar zhang

Enabling Listener Trace ,TNS-01251 Oracle version 11g introduced the ADR or Automatic Diagnostic Repository feature,Trying to change the log file using the Lsnrctl utility fails with: TNS-01251: Cannot set trace/log directory under ADR. oracle@db231 trace]$ lsnrctl status LSNRCTL for Linux: Version 11.2.0.3.0 – Production on 15-AUG-2013 14:15:59 Copyright (c) 1991, 2011, Oracle. All rights reserved. … Read more

export data from 11g and import into 10G R2 ORA-01455

2013-08-13 by weejar zhang

EXP-00008: ORACLE error 1455 encountered
ORA-01455: converting column overflows integer datatype
EXP-00000: Export terminated unsuccessfully

Dynamic SQL Supports Statements Length Characters Limit (execute immediate sql长度限制)

2013-08-08 by weejar zhang

有时需要在plsql 写一些动态sql,用execute immediate 或dbms_sql 调用，但是execute immediate 后动态sql 文本的长度限制是多少呢？

To hold the latch manually, DB hang demo(手动持用latch使数据库hang)

2013-08-07 by weejar zhang

It is widely known that the Oracle server uses kslgetl – Kernel Service Lock Management Get Latch function to acquire the latch,oradebug call kslgetl/kslfre can be used to acquire the latch manually. This is very useful to simulate latch related hangs and contention.

Delete the data on the table very slow(删除数据慢)

2013-08-06 by weejar zhang

今天开发的同事问有个表上的数据为什么删不掉？我看了一下，也就不到100000条数据，表上有外键，等了5分钟hang在那里…

Know more about Oracle ASH

2021-01-152013-07-25 by weejar zhang

《Know More about Oracle AWR》姐妹篇，oracle 10g引入，ASH 是性能诊断工具，不像sql trace总是默认打开，保存历史上发生了什么，提供比AWR更细粒度的数据，即使当系统负载很高时，它也工作的很好，因为使用类似memcopy的数据收集，不会有太大的额外负担，没用任何类型的数据库lock。 Active(‘Active’ == Non-idle sessions) Session History Licensed as part of the Diagnostic pack,