Tuning “transaction” & TX lock wait event ,speeding up rollback dead transaction

Yesterday I received a warning and a production db instance found many TX lock and wait event “transaction”, I check the TX lock model is 6, so we can make sure is caused by multiple sessions update the same data, and wait event “transaction” is relatively rare, Here the record about my diagnosis method.

ORA-01135 ORA-01110 check offline tablespace in alert.log

My case is 2 nodes RAC on aix,The previous we do move all objects on a tablespace to new tablespace For reasons of space Fragment, and alter the original tablespace offline. But ORA-01135 ORA-01110 error in the alert.log file I keep seeing the message every 10 minutes


Troubleshooting ORA-01031: Insufficient Privileges issue

1, Login in remote instance using sqlplus as sys when the target db instance password file not exists or file name is wrong.
2, If you try to execute DBMS_SESSION.SET_CONTEXT


Autotask(Optimizer statistics gathering) not working in未自动收集统计信息)

有一些表数据发生了很大变化,但是统计信息从初次导入后从没有自动收集过统计信息,导致现在的有些执行计划不成确, 手动收集是可以成功的,如何开启自动收集? oracle RAC ON AIX


IMPDP hangs, session wait “wait for unread message on broadcast channel”

昨晚有个朋友说加班在IMPDP数据, 在导入中途突然没有了进展,挂在那里不动了,impdp 窗口也没有报错, 一直等了1个多小时,说是impdp使用了parallel,怀疑是parallel参数出了问题, 最终其实原因很简单。这里只是简单的描述遇到这类问题时的处理思路。

Duplicate (Clone) Oracle Database to the Same Machine (同一机器数据库还原)(二)

When an DB operation error occurred , and flashback technique can not be used, you can use this way do a database point in time recover on same db server, to clone a new db to recover, then drop.

Duplicate (Clone) Oracle Database to the Same Machine (同一机器数据库还原)(一)

Starting with Oracle 11g there are now two ways to clone a database:
1. Active Database Duplication
2. Backup-based Duplication

Exp-00003 no storage definition found issue in oracle 11g (未找到段 (0,0) 的存储定义)

. 正在导出表 ANBOB_CREDIT导出了 6 行
EXP-00003: no storage definition found for segment (0, 0)
. . 正在导出表 ANBOB_MODEL导出了 1 行
. . 正在导出表 ANBOB_FILE

How to drop ASM DiskGroup in RAC? (DISKGROUP删除后db资源显示OFFLINE)

to chose sqlplus “drop diskgroup”. however,the diskgroup that dropped is still listed as a resource. , Actually, the DB is open still, check alert log

ora-00313,ora-00312 ora-17503, ora-15001


Add ORACLE Listener Fail or ORA-125XX, Don’t forget “Run as Administrator”(以管理员身份运行) on windows7/8

She had with installation of Oracle 11R2 on Windows 8 (64-bit). The issues I faced The errors can’t connect database using Listener Service.and can’t to add new listener.

Export terminates with ORA-00600 [ksuloget2]

. . exported “ANBOB”.”ANBOB_PROJECT_SCORE” 3.931 GB 46241981 rows
. . exported “ANBOB”.”T1″
EXP-00056 Oracle error 600 encountered
ORA-00600: internal error code, arguments: [ksuloget2], [0xFEBDD104], [0xFEBCEE54], [500], [0xFEBDD128], [], [], [], [], [], [], []
. . exported “ANBOB”.”T2″

The segment header block corrupted cause ORA-08103 issue (段头坏块导致ora-8103)

节前有个网友向我咨询他们的生产库遇到了ora-8103,错误的block 是 SEGMENT HEADER BLOCK, 不可以简单通过rowid 跳过, 也不能像修改data block corruption 那样通过bbed 修改块为 corrupted 然后通过 dbms_repair.skip_corrupt_blocks 跳过该块, 该segment header block上都没有extent 信息(如extent map\HWM)…

Recover from rm -rf deleted datafile in NOARCHIVELOG mode using BBED

A friend from QQ Group find me, he removed a online datafile from the his production database, but for as long as the database remains up. he re I take a demo to show recovery process. …

Identifying Shared Memory Segments for multiple database(Disable AMM) 标识某实例的共享内存段ID

有时oracle 实例异常终止,会导致oracle process killed,但是实例之前所分配的shared memory segments没有release, 而此时登录提示no login,而且本机还有其它实例在用无法kill 所有…

ORA-07445 [ACCESS_VIOLATION] [unable_to_trans_pc] [UNABLE_TO_READ] Troubleshooting

Today I to read a SR, saw a case , to face a ora-7445 internal error when open resetlogs database after do database recovery. So here I collected some ora-7445 [unable_to_trans_pc] [UNABLE_TO_READ] errors with frequently ways to Troubleshooting .

oracle 12c new feature: In-memory option VS in memory standard row-major

Oracle 发布引入了一系列的新特性,当然还有关注度非常高的ORACLE In-Memory Option,在内存中提供一种列级的存储, 在OLTP中提供更好的性能,当然在Exadata中ORACLE已在存储级提供了列级的性能优化hybrid columnar compressed (HCC) format…

Where is stored Initialization Parameter(spfile) for PDB in Oracle 12c (PDB参数文件存在哪里)

12c引入的可插拔的数据库容器(Multitenant Database)框架,在CDB中容器中的有1个或多个(Pluggable Databases)PDB,同时有一些参数是可以在PDB级别修改, 我们暂时称为PDB local parameter, PDB 级的参数对于PDB自身影响会覆盖(优先)从CDB继承的参数…

ORA-600 [kdBlkCheckError][X],[X],[38504] and ORA-600[4194],[],[] in

The Oracle Database is crashing down in few minutes as soon as we start the Database. DB in linux single instance . it is in VMWare 6, Done a dynamic disk allocation before the problem occurred . then check alert log found ORA-600 [kdBlkCheckError] and ORA-600[4194] errors.

Inserting no value for the column NOT NULL and no explicit DEFAULT clause refused , After upgrade MySQL5.6 default

前段时间升级MySQL到了5.6,但是后来app 后台日志显示一些SQL insert 出错,手动执行提示有些字段没有default值,查看了表语法该字段是Not null,而且升级也是OS copy数据库文件(因为是MyISAM 引擎),对比升级前后表结构一致…

orphaned processes not cleanup when using resource limit(profile) in 9i RAC, cause skgpspawn failed(进程不回收)

Why is my database after running for some time , large number of database server processes will be created , but the number of sessions is very little, what actions cause orphaned processes? And sometimes hit ora-20 error..