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…
weejar zhang
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 12.1.0.2 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 11.2.0.4
The Oracle Database is crashing down in few minutes as soon as we start the Database. DB 11.2.0.4 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..
Oracle 12c new Feature: JSON Support in the Oracle 12c Database RDBMS(从此oracle rdbms支持JSON)
很久前在国外的一个blog就看到说是oracle RDBMS(not NOSQL)要支持JSON, 当时说是XMLDB 开发组在做这个事情，随着oracle 12.1.0.2 release 得到确认，的确引入这一特性，JSON, JavaScript Ojbect Notation 在结构上和XML有很多相似之处, 而且这种Schema less data management的数据模型在NOSQL 中广泛应用，数据的存储相对更加紧凑，避免有时空列致ORACLE RDBMS中表一些数据”洞”…
Troubleshooting Query fail with Ora-600 [kdsgrp1] ora-600 [qertbFetchByRowID]
ora-600 [kdsgrp1] 发生fetch 操作查找预期的行失败时, 常有ora-600 [qertbFetchByRowID] 伴随，这次遇到的一个aix 10.2.0.4 rac案例有 ora-7445 [kdr9ir2F0rst4srp0+0068] 和 ora-600 [25027], [6], [825242163] 陪伴, 而且 ora-600 [25027] 的rdba 莫名指向了一些不相干数据块..
DataPump Export (EXPDP) Error ORA-39095 Dump File Space Has Been Exhausted Possible solution
ORA-39095 : ” dump file space has been exhausted. Unable to allocate 8192 bytes”
HOW do I fix the ORA-39095 error?
Answer:
There are several likely reasons for this error:…
ORA-00600: internal error code [kkmupsViewDestFro_4] in oracle 11.2.0.1
The ORA-600 [KKMUPSVIEWDESTFRO_4] happens while running a merge statement with join elimination. Such join elimination can only happen if the fix for bug 7679164 is present and enabled. This fix was included in the 11.2.0.1 base release.
GOLDENGATE FILTER row data with Operation-System environment variable(通过操作系统环境变量Filter数据)
昨天有个朋友在网上问如何在用GOLDENGATE 一对多的同步模式下，简化配置，到达统一的OGG Replicat配置文件同时过滤数据的目的。 好比总部更新数据， 分销商只同步自己的数据， 但是如果有400个分销商，为了简化安装不重复性的修改OGG replicat配置文件，所以OGG TARGET(分销商)使用相同的配置文件， 但是在OGG 的配置文件中使用比较灵活的操作系统变量…
Some interesting about oracle, did you know? (一)
By default DBUA removes all the hidden parameters during upgrade.If you want to keep the hidden parametersinvoke DBUA with ‘keepHiddenParams’ option.e.g./dbua -keepHiddenParams
ora-942 or ora-1775 or PLS-00201 When using a database link in a stored procedure
有一个procedure中一段SQL用到了synynom,而synonym指向一个dblink所对应的表，其中是两个子查询做了full join,在procedure 编译时提示ORA-00942: table or view does not exist，而把那段plsql 查询语句块拿出来，做为单条SQL执行时完全正常且有返回结果…
oracle 12c new feature: RESOURCE role without unlimited tablespace
If you are grant privilege to new account like this “grant connect, resource to username”, as you know from 11g the role “Connect” only have “create session” privilege , but now in 12c ,the role “Resource” privilege had changed too.
SQL join problem caused by Low cardinality with Histogram(柱状图产生的过低Card.导致表join性能问题)(二)
接上一篇 http://www.anbob.com/archives/2323.html 下面我们从统计信息入手 sys@DEVDB>select count(distinct join_course_count),count(distinct is_course_qual),count(*) from app_zyyjhj.em_examinee; COUNT(DISTINCTJOIN_COURSE_COUNT) COUNT(DISTINCTIS_COURSE_QUAL) COUNT(*) ——————————– —————————– ——————– 6 4 35765 #使用tabstat2 脚本收信表信息，我已截断输出 sys@DEVDB>@tabstat2 em_examinee app_zyyjhj Table Number Empty Average Chain Average Global User Sample Date Name of Rows Blocks Blocks Space Count Row Len Stats Stats Size MM-DD-YYYY ————— ————– ——– ———— ——- ——– ——- —— —— … Read more
SQL join problem caused by Low cardinality with Histogram(柱状图产生的过低Card.导致表join性能问题)(一)
当CBO产生的Cardinality过低，尤其是在表之间关连时，往往会差之毫厘差之千里，甚至影响表之间的join方式，注意下MERGE JOIN CARTESIAN部分，这里使用了一种NL style的MJ,..
The filter pushed in subquery issue in oracle 11G (filter推进子查询)
注意上面的4# 计划 的fileter 部分， 这就是问题的根源。了解SQL的执行步骤应该清楚在sql parse阶段CBO会帮我们做sql查询转换生成高效的执行计划, 在本案例我们想把TO_NUMBER(“S”.”SCORE”)<60 的条件放到子查询返回的结果集后再过滤, 结果CBO错误把此条件提前和该字段的其它条件一并执行..
ORACLE异机表空间基于时间点恢复 (TSPITR) Method(恢复部分表空间)
RMAN Tablespace Point-In-Time Recovery ( TSPITR) enables you to quickly recover one or more tablespaces in an Oracle database to an earlier time, without affecting the state of the rest of the tablespaces and other objects in the database.
ORACLE异机数据库基于时间点的恢复 (DBPITR) Method
DBPITR enables you to recover a database to some time in the past.I will demonstrate below how to do flashback a database to a point in time.