修改11g r2 RAC SCAN IP
SCAN简化了客户端连接的配置，只需指定SCAN Name在客户端的tnsnames.ora，不需要知道每个节点的vip就可以实现负载均衡
每个节点上的pmon会经常的发送本节点的负载情况到scan listener…
weejar zhang
揭秘 Oracle 11gR2 RAC ASM Instance 启动
存储asm instance spfile到asm，听上去很奇怪，启动自身，首先要解决的几个问题
1,asm diskgroup 没mount,如何读spfile?
2,在oracle_home/dbs下没有参数文件，如何知道spfile在哪?
3,不知道spfile，怎么知道的asm_diskstring?
11G R2 Oracle Local Registry(OLR)
从oracle 11R2版本起在网格计算领域引进了新特性，其中之一就是grid Oracle Local Registry(OLR)，做为oracle clusterware的一部分，有些人喜欢叫Oracle Local Repository，因为这repositery记录了本地资源的信息和配置..
move rdbms from local file(no-ASM) to ASM instance
one asm instance can support multiple rdbms instances,and it is possible to run more than one asm instance to which the rdbms instance could connect,this potential many-to-many relationship btween the instance types is resolved by the cluster services.
about modify unique constraint
ERROR at line 2:
ORA-02299: cannot validate (ICME.UK_PROJECT_SCORE) – duplicate keys found
oracle ASM on LVM (linux卷管理),配置LVM
LVM在后期因先前指定的路径空间不够时调整起来很方便，也可以就用于ASM，但是并不推荐ASM安装在LVM之上，因为LVM的功能在ASM上已存在。
oracle 11g BaseLine(基线)指定application中不可修改sql的执行计划
11G前有sql profile、outline可以稳定执行计划，但有些文档中指出有时outline指定了但也有要能走新的执行计划，所以11g的BASELINE是OUTLINE的改进版。一般应用在版本升级或稳定特定SQL的执行计划，也可以修改指定SQL的执行计划，当OUTLINE与BASELINE有同时指定时BASELINE有优先权。
noarchive model,迁tablespace从ASM到Local files fs
利用rman 可以方便的把datafile,tablespace,database在本地文件系统和ASM之间转换
10gGridControl failed to start a managed process after the maximum retry limit
[oracle@dbserver1 bin]$ ./opmnctl startall
failed to start a managed process after the maximum retry limit
[error 13079] [ecid: -] No matching CACHE element found in
sqlserver 游标小例
总忘，小记 declare @c int declare @seq int set @seq=54000101 declare cur cursor for SELECT sectionid FROM StudySection WHERE (yearSemesterID = 2012001) open cur fetch next from cur into @c WHILE @@fetch_status=0 begin set @seq=@seq+1 print @seq update StudySection set oracleid=@seq where sectionid=@c fetch next from cur into @c end close cur deallocate cur
materialized view query rewrite and ORA-30353
启用物化视图的重写有两个条件QUERY_REWRITE_ENABLED=true and materialized view enable query rewrite.
在CBO对查询sql 重写后估算cast后直接查询mv
after OS reboot ,11g RAC asm not automatic startup ORA-27102
[ohasd(4507)]CRS-2807:Resource ‘ora.asm’ failed to start automatically.
SQL> startup nomount
ORA-27102: out of memory
OEL5.8 Install RAC Grid 11203 PRVF-5184 : Check of following Udev attributes failed
PRVF-5184 : Check of following Udev attributes of “rac2:/dev/asm-diskc” failed: “[Owner: Found=’root’ Expected=’grid’, Group: Found=’root’ Expected=’asmadmin’, Permissions: Found=’0600′ Expected=’0660′]”
11gr2 install database加大AMM内存时INS-35171
Oracle Error :: INS-35171
Target database memory (stringMB) exceeds at least one of the selected nodes available shared memory (string MB).
rac 11203 grid 安装PRVF-5636 : The DNS response time for an unreachable node exceeded “15000” ms
OUI默认是带域名的名称如znode1.anbob.com/znode1-vip.anbob.com,去掉改为了znode1/znode1-vip 新增加的znode2/znode2-vip，再下一步到检查的时，检查通过。
Never bind peeking or Wrong execution plan?
注意当用veriable变量绑定时sqlplus autotrace有可能显示的执行计划不是实际的，用dbms_xplan.display_cursor查看
RHEL/OEL 5启用xmanager 远程桌面x
For XDMCP connection to Red Hat 5 EL or CentOS 5 or OEL5
1. Change runlevel to 5
Open /etc/inittab and set the initial runlevel to 5 as following:
id:5:initdefault:
11gr2安装Grid 时 node2 root.sh失败Start of resource “ora.asm -init” failed
Start of resource “ora.asm -init” failed
Failed to start ASM
Failed to start Oracle Clusterware stack
11gr2安装Grid 时 ins-40719 ins-40912
ins-40719 ipaddress configured for single client access name(scan):
rac-scan.anbob.com is already assigned to another system
ORA-00600: internal error code, arguments: [Skgmfail] 案例
数据库在运行一段时间后crash,遭遇ORA-00600: internal error code, arguments: [SKGMFAIL], [2], [4], [4], [1]，重启后又可以正常运行。