18 11, 2008
ORACLE的工作机制
zt
http://blog.oracle.com.cn/index.php/34012/viewspace-4553.html
第一次在自己的BLOG上贴我自己写的"ORACLE的工作机制"。
12 11, 2008
关于Freelists和Freelist Groups的研究
5 05, 2008
sqlnet.expire_time and IDLE_TIME
当设置了resource_limit=true 。通过idle_time限制session idle 时间。session idle超过设置时间，状态为sniped (v$session).,然而OS下的process并不会释放，当session(user process) 再次与server process 通讯，将关闭相应的server process.
sqlnet.expire_time 的原理不一样，Oracle Server 发送包探测dead connection ，如果连接关闭，或者不再用，则关闭相应的server process.
以上两者组合使用，减少server process,防止process超过init$ORACLE_SID极限值。
查看全文20 04, 2008
Oracle Freelist和HWM原理及性能优化(zt)
http://www.bitscn.com/oracle/optimize/200611/82295.html
Oracle Freelist和HWM原理及性能优化
http://www.akadia.com/services/ora_freelists.html
The Secrets of Oracle ASSM and FreelistsFreelist
查看全文9 04, 2008
When to Implement Parallel Execution
environments. Complex queries, such as those involving joins of several tables or
searches of very large tables, are often best executed in parallel.
Parallel execution is useful for many types of operations that access significant
amounts of data. Parallel execution improves processing for:
* Large table scans and joins
* Creation of large indexes
* Partitioned index scans
* Bulk inserts, updates, and deletes
* Aggregations and copying
You can also use parallel execution to access object types within an Oracle database.
For example, use parallel execution to access LOBs (large objects).
Parallel execution benefits systems that have all of the following characteristics:
* Symmetric multi-processors (SMP), clusters, or massively parallel systems
* Sufficient I/O bandwidth
* Underutilized or intermittently used CPUs (for example, systems where CPU usage is typically less than 30%)
* Sufficient memory to support additional memory-intensive processes such as sorts, hashing, and I/O buffers
If your system lacks any of these characteristics, parallel execution might not significantly improve performance. In fact, parallel execution can reduce system performance on overutilized systems or systems with small I/O bandwidth.
8 04, 2008
本地管理表空间(itpub精华贴)
31 03, 2008
Knowing when to Rebuild Indexes
Brian Peasland
Database Administrator
EROS Data Center
3 February 2000
24 03, 2008
行迁移和行链接
row chain：When a row is too large to fit into any block, row chaining occurs. In this case, the Oracle devide the row into smaller chunks. each chunk is stored in a block along with the necessary poiters to retrive and assemble the entire row.
row migration：when a row is to be updated and it cannot find the necessary free space in its block, the Oracle will move the entire row into a new block and leave a pointer from the orginal block to the new location. This process is called row migration.
12 03, 2008
Identifying Unused Indexes with the ALTER INDEX MONITORING USAGE Command
10 03, 2008
Oracle External Procedure to Run Host Commands
6 01, 2008
High Availability Enhancements In Oracle9i
5 01, 2008
Partitioning an Existing Table using EXCHANGE PARTITION
Partitioning an Existing Table using EXCHANGE PARTITION
查看全文5 01, 2008
DB Bocks gets，Consistent gets And Physical reads（转）
physical reads 物理读
db block gets ---current mode read
consistent gets ---一致性杜
db block gets+consistent gets=逻辑读 查看全文
3 01, 2008
diagnosing systems that are hung on locks
$ORACLE_HOME/rdbms/admin/catblock.sql
Create views of oracle locks
$ORACLE_HOME/rdbms/admin/utllockt.sql
Print out the lock wait-for graph in tree structured fashion. This is useful for diagnosing systems that are hung on locks.
26 12, 2007
Using Oracle's Parallel Execution Features
Using Oracle's Parallel Execution Features
查看全文20 12, 2007
关于database link 和 domain 和 global name
Database Global Names
The GLOBAL_NAMES Parameter
查看全文18 12, 2007
Windows上Oracle开放防火墙端口问题
http://www.cnblogs.com/applengine/archive/2007/11/19/963648.html
要使Oracle客户端能正常连接到设置有防火墙的安装在windows上的Oracle服务器，单开放一个1521或自定义的监听端口是不够的。
查看全文7 12, 2007
OMS使用-安装配置OMS
oracle应用（如console) ---> oracle management server ---> intelligent agent 查看全文
5 12, 2007
The life of an SQL statement
http://www.adp-gmbh.ch/ora/concepts/sql_stmt.html
http://www.adp-gmbh.ch/ora/concepts/cursors.html
SQL的处理流程-基础
http://fusnow.itpub.net/post/681/211741
Open cursors
Cached cursors
3 12, 2007
安装oracle 9.2.0.8 -- 安装oracle 9.2.0.1.0 -- Installation & post-Installation
3 Installation
4 Post-Installation
查看全文1 12, 2007
安装oracle 9.2.0.8 -- 安装oracle 9.2.0.1.0 -- Pre-Installation
安装 9.2.0.8 升级包 查看全文
1 11, 2007
SYS_CONTEXT
7 09, 2007
2分钟让你明白什么适ERP(精彩)
ERP(Enterprise Resource Planning)企业资源计划系统，是指建立在信息技术基础上，以系统化的管理思想，为企业决策层及员工提供决策运行手段的管理平台。
http://rainbowbridg.itpub.net/category/23663/43039 查看全文
18 08, 2007
set transaction name
17 08, 2007
exp工具导出几个schema的数据
由于磁盘故障，cp，rman都会I/O出错。
幸运的是，exp,imp逻辑备份工具还可以用。
So
crontab运行exp脚本exp数据。
查看全文15 08, 2007
一个小小的冷备脚本
创建了catalog database ,更好的利用rman的强大功能。
不过我创建的时候有些怪怪的，没有选择rman用户。这点做得有些不专业。
这个数据库如果崩溃还是可以忍受一定的数据损失的，因为控制文件内有备份的信息。计划每周冷备一次。以下是冷备脚本。
10 12 * * 6 /backup/oracle/veritas_coldbackup.sh > /dev/null 2>&1
12 08, 2007
PASSWORD_REUSE_TIME and PASSWORD_REUSE_MAX（10g和9i不同）
12 08, 2007
oracle 帖子收集
如何从表空间中“删除”数据文件
Oracle的日期函数
数据库当前状况脚本
快照控制文件
参数CONTROL_FILE_RECORD_KEEP_TIME和MAXLOGHISOTRY
利用DBMS_METADATA包获取权限信息
在ORACLE里按用户名重建索引的方法
Oracle]Data Guard数据库灾难防护
如何学习Oracle-eygle的方法经验谈
在UNIX裸设备和文件系统之间移动ORACLE
Oracle如何处理身份管理
Oracle10g 移植到 Oracle ASM
bbed的心得
dissassembling_the_data_block.pdf (google，一个老外写的bbed的文档，没时间看，以后看)
Recompiling Invalid Schema Objects
10 08, 2007
安装配置OMS
oracle OMS 为三层架构。
oracle应用（如console) ---> oracle management server ---> intelligent agent
安装步骤：
查看全文9 08, 2007
Orace 8i Rman 示例脚本
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