Troubleshooting ora-07445 [__lwp_kill()+48] [SIGIOT] error and instance crash
Exception [type: SIGIOT, unknown code] [ADDR:0x6CA9] [PC:0xC0000000003125F0, __lwp_kill()+48] [exception issued by pid: 27817, uid: 1024] [flags: 0x0, count: 1]
Errors in file /oracle/app/oracle/diag/rdbms/anbob/anbob1/trace/anbob1_lms3_27817.trc (incident=704134):
ORA-07445: exception encountered: core dump [__lwp_kill()+48] [SIGIOT] [ADDR:0x6CA9] [PC:0xC0000000003125F0] [unknown code] []
After OS reboot, Ohasd(cssd) start fail is due to OLR corrupted
前几天帮助同事处理了个案例， 主机意外重启后数据库无法启动， 环境是11.2.0.3 standalone o […]
Troubleshooting Instance crash when modify db_cache_size, ora-600 [kmgs_pre_process_request_6]
ORA-00600: internal error code, arguments: [kmgs_pre_process_request_6], [6], [895], [0], [3], [0x459C1F3D8], [], []
Mon Dec 22 22:40:43 2014
MMAN: terminating instance due to error 822
Instance terminated by MMAN, pid = 31205
Troubleshooting ORA-12012&ORA-29283&ORA-06512 issue
ORA-12012: error on auto execute of job “ORACLE_OCM”.”MGMT_CONFIG_JOB_2_2″
ORA-29283: invalid file operation
ORA-06512: at “SYS.UTL_FILE”, line 536
ORA-29283: invalid file operation
ORA-06512: at “ORACLE_OCM.MGMT_DB_LL_METRICS”, line 2436
ORA-06512: at line 1
Oracle Database History
In 1977 Larry Ellison saw a IBM Journal of Research and Development, discovered a research paper that described a working prototype for a relational database management system (RDBMS). Showing it to coworkers Bob Miner and Ed Oates at Ampex .
How to release still “killed“ status session in v$session?(释放killed的session)
最近在一套生产库上发现了几个已经killed的会话一直保持在v$session 会话中，会话是user type的连接，而且已经killed了很久，通过SPID 发现操作系统层面已不存在该进程， 下面是我多次尝试后最终释放，
How to find out who caused the database user locked（ora-1017 or ORA-28000）(捕捉登录失败)
昨天有应用反应server日志中有如下错误，提示用户locked，但是重启了下web server又恢复了正常，但是这期间我们也没有人为的给db user unlock, 下面记录一下, 其实事情的经过是这样子的…
Corrupted free block & ORA-19566 when using rman backup after restore DB
RMAN-00569: ========= ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: =====================================================
RMAN-03009: failure of backup command on ORA_DISK_1 channel at 03/10/2015 12:18:24
ORA-19566: exceeded limit of 0 corrupt blocks for file E:\ORACLE2\PRODUCT\10.1.0\ORADATA\ORCL\USERS01.DBF
kjfspseudorcfg and kjxgrrcfgchk some reason #
kjxgrrcfgchk: Initiating reconfig, reason=3 #######<<<<<<<<< kjxgrrcfgchk: COMM rcfg - Disk Vote Required kjfmReceiverHealthCB_CheckAll: Recievers are healthy.
Online Redefinition Partition Existing Table, ora-600 [kkzuord_copycolcomcb.2.exec] and ORA-23539
从9i起可以重定义表结构可以在线，对于在线重定义的好处很多站点都有这里不再叙述，原理也是利用了mview及mview log 的低层操作， 满足对于7*24 小时业务的在线调整， 但是需要增加原大小一倍的空间存放临时数据
Troubleshooting TNS-12547&TNS-12560 AIX error 32: Broken pipe caused by tcp socket leak
上周出现个蹊跷案例，最近一直在忙今天简单的记录一下， 中间件反馈数据库连接时失败，在数据库使用lsnrctl status 查看监听状态会发现Listener一会儿正常，一会儿报错，但是在Listener正常时可以看出listener的start date并没有restart过
Tuning: latch: cache buffers chains 又一案例
CBC latch竞争的原因很多，通常也可以理解为一种热块， 对于CBC 通常都是从session wait中找到child latch address 然后再去x$bh的hladdr字段找到相应的obj，1个BH handle可以会关连多个obj, 再参考TCH 列确认比较hot的对象。大多数CBC的OLTP系统多数应该注意一下sql 的执行计划中使用了NL join的方式；
Troubleshooting ora-12519 or ora-12516 ,listener service ‘blocked’, and wait event ‘latch: ges resource hash
通常当出现ora-12519 or 12516时都是因为数据库进程数超过了数据库参数processes 或 sessions 时， 并且通常在db alert 中出现ora-20 or ora-18 的错误信息，如果当时查看监听服务状态使用lsnrctl service 会发现service 当时是”blocked”状态
How to list all db links in oracle DB to generate a flat file? (生成dblink列表文件)
自己整理了个简单的SHELL 去收集LOCAL 的所有DB LINKS，功能是如果DB LINK创建使用的是简单方式（没有配置TNSNAMES.ORA）直接取IP:PORT, 或如果使用TNSNAME Alias Name调用TNSPING 转换成IP, 同时还会判断tnsping ip port 里否通?
Index partition unusable and wait ‘kpodplck wait before retrying ORA-54’ event during direct sqlldr
最近有人遇到用SQL*Loader 向数据库加载数据时发现很慢，并且反映有几个分区表上的local索引总是递归的变成invalid or unusable，rebuild该分区失效索引，另一个索引分区又失效。
Acquiring Management Agent Software for HPUX&AIX in the Offline Mode(离线安装EM agent)
OMS安装在OEL 6.6 ，Product DB Agent 都是在AIX, HPUX, EXADATA(linux)平台, linux平台的比较方便安装，因为OMS 自带相同平台的AGENT,其它平台需要先在OMS下载相应的AGENT支持，这里有OMS是在OFFLINE模式
RMAN-06900&RMAN-06901 RMAN-00600 [3045] ORA-19921 when rman connect target
RMAN-00571: ===========================================================
RMAN-00554: 内部恢复管理器程序包初始化失败
RMAN-00600: internal error, arguments [3045] [] [] [] []
Performance Tuning DML hang wait event ‘cursor: pin S wait on X’
年前一套数据库出现了性能问题，一周出现了两次，很多session 等待“cursor: pin S wait on X” 事件，这是一套11.2.0.4 RAC on RHEL6 的环境，下面记录一下该案例的优化方案。
