As you can see from above screenshot of MetaLink, 11.1.0.7.0 Patch Set for ORACLE Database Server for HP-UX Itanium is released on 06-OCT-2008.

And I’m so proud to make contribution to this release. Cheers!

V$SYSTEM_EVENT视图显示了数据库实例（instance）启动以来所有会话（session）所遇到的所有等待事件的累计统计信息（aggregated statistics）。

SQL> desc v$system_event
Name                                      Null?    Type
—————————————– ——– —————————-
EVENT                                              VARCHAR2(64)
TOTAL_WAITS                                  NUMBER
TOTAL_TIMEOUTS                            NUMBER
TIME_WAITED                                   NUMBER
AVERAGE_WAIT                                 NUMBER
TIME_WAITED_MICRO                       NUMBER
TOTAL_WAITS_FG                              NUMBER
TOTAL_TIMEOUTS_FG                        NUMBER
TIME_WAITED_FG                               NUMBER
AVERAGE_WAIT_FG                            NUMBER
TIME_WAITED_MICRO_FG                   NUMBER
EVENT_ID                                           NUMBER
WAIT_CLASS_ID                                  NUMBER
WAIT_CLASS#                                      NUMBER
WAIT_CLASS                                       VARCHAR2(64)

其中EVENT列包含了等待事件的名称，TOTAL_WAITS列包含了会话等待该事件的次数。TIME_WAITED显示了等待该事件所花费的总时间。

V$SESSION_EVENT视图

V$SESSION_EVENT视图显示了当前连接到实例上的所有会话的等待事件的累计统计信息。

SQL> desc v$session_event
Name                                      Null?    Type
—————————————–
SID                                                   NUMBER
EVENT                                              VARCHAR2(64)
TOTAL_WAITS                                  NUMBER
TOTAL_TIMEOUTS                            NUMBER
TIME_WAITED                                   NUMBER
AVERAGE_WAIT                                 NUMBER
MAX_WAIT                                         NUMBER
TIME_WAITED_MICRO                        NUMBER
EVENT_ID                                          NUMBER
WAIT_CLASS_ID                                 NUMBER
WAIT_CLASS#                                     NUMBER
WAIT_CLASS                                      VARCHAR2(64)

V$EVENT_NAME视图并不是一个动态视图，它的内容不会随着时间的推移而变化。它是一个包含了你的数据库实例所定义的所有等待事件（wait events）的名字的参考视图。等待事件的数量随着数据库版本的不同而不同，并且也依赖于所安装的数据库选项（option）：

$ sqlplus / as sysdba

SQL*Plus: Release 11.1.0.6.0 – Production on Tue Sep 23 01:33:39 2008

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 – 64bit Production
With the Partitioning, Real Application Clusters, OLAP, Data Mining
and Real Application Testing options

SQL> desc v$event_name
Name                                      Null?    Type
—————————————–
EVENT#                                             NUMBER
EVENT_ID                                          NUMBER
NAME                                                VARCHAR2(64)
PARAMETER1                                     VARCHAR2(64)
PARAMETER2                                     VARCHAR2(64)
PARAMETER3                                     VARCHAR2(64)
WAIT_CLASS_ID                                 NUMBER
WAIT_CLASS#                                    NUMBER
WAIT_CLASS                                      VARCHAR2(64)

SQL> select count(*) from v$event_name;

COUNT(*)
———-
961

一个简单的COUNT(*)就可以告诉你你的数据库中定义了多少个等待事件。

每个等待事件拥有最多3个属性（attributes），它们分别被记录在PARAMETER1，PARAMETER2和PARAMETER3列中。同时，这3列的值也将会显示在V$SESSION_WAIT视图的P1TEXT，P2TEXT和P3TEXT列中。

This year, there are 4 members of our group (in OARDC Shenzhen) have the opportuinity to participate this world’s largest conference for Oracle customers and technologists. But for me, I think I have to wait for OpenWorld 2009 or 2010

最近尝试了一下将Oracle Clusterware 11gR1的OCR和VD放在OCFS2上，这里记录一下OCFS2的安装过程。

首先是确定所使用的Linux的发行版本（distribution），内核版本（version）和风格（flavor），处理器架构：

# cat /etc/redhat-release
Enterprise Linux Enterprise Linux AS release 4 (October Update 5)

# uname -r
2.6.9-67.0.4.0.2.ELsmp

# uname -p
i686

可以看到这里我使用的是Oracle Enterprise Linux 4u5（可以认为是等同于Red Hat Enterprise Linux 4u5），内核版本是2.6.9-67.0.4.0.2，内核风格是smp，处理器架构是i686（也就是x86）。

接下来按照上面的信息去下载相应的OCFS2和OCFS2 Tools（包括ocfs2-tools和ocfs2console）的RPM包。

# wget -c http://oss.oracle.com/projects/ocfs2/dist/files/RedHat/RHEL4/i386/1.2.9-1/2.6.9-67.0.4.EL/ocfs2-2.6.9-67.0.4.ELsmp-1.2.9-1.el4.i686.rpm
# wget -c http://oss.oracle.com/projects/ocfs2-tools/dist/files/RedHat/RHEL4/i386/1.2.7-1/ocfs2-tools-1.2.7-1.el4.i386.rpm
# wget -c http://oss.oracle.com/projects/ocfs2-tools/dist/files/RedHat/RHEL4/i386/1.2.7-1/ocfs2console-1.2.7-1.el4.i386.rpm

删除掉现有的老版本的OCFS2相关RPM包：

# rpm -qa | grep ocfs | xargs rpm -e

依次安装刚刚下载的3个RPM：

# rpm -ivh ocfs2-tools-1.2.7-1.el4.i386.rpm
# rpm -ivh ocfs2console-1.2.7-1.el4.i386.rpm
# rpm -ivh --nodeps ocfs2-2.6.9-67.0.4.ELsmp-1.2.9-1.el4.i686.rpm

注意安装OCFS2 RPM时需要加上“–nodeps”选项。

这里还有一个问题，上面安装的OCFS2 RPM的内核版本（2.6.9-67.0.4）与我所使用的Linux的内核版本（2.6.9-67.0.4.0.2）并不完全一致，所以还需要进行下面的额外工作：

# cp -r /lib/modules/2.6.9-67.0.4.ELsmp/kernel/fs/* /lib/modules/2.6.9-67.0.4.0.2.ELsmp/kernel/fs

至此，OCFS2的安装已经完成。

OCFS2

Open-iSCSI

A discussion on OCFS, OCFS2, ASM, RAW

Complete product portfolio

Open

Open standard and open source

Integrated

Integrated products

You can manage primary and standby databases using the SQL command-line interface or the Data Guard broker interfaces, including a command-line interface DGMGRL and a graphical user interface that is integrated in Oracle Enterprise Manager.

Primay Database

A Data Guard configuration contains one production database, also referred to as the primary database, that functions in the primary role. This is the database that is accessed by most of your applications.

The primary database can be either a single-instance Oracle database or an Oracle Real Application Clusters (RAC) database.

Standby Databases

A standby database is a transactionally consistent copy of the primary database. Using a backup copy of the primary database, you can create up to 9 standby databases and incorporate them in a Data Guard configuration. Once created, Data Guard automatically maintains each standby database by transmitting redo data from the primary database and then applying the redo to the standby database.

Similar to a primary database, a standby database can be either a single-instance Oracle database or an Oracle RAC database.

The types of standby databases are as follows:

• Physical standby database
• Logical standby database
• Snapshot standby database

As you can see from above screenshot of MetaLink, 10.2.0.4.0 Patch Set for ORACLE Database Server for AIX5L Based Systems (64-bit) is released on 15-MAY-2008.

And I’m so proud to make contribution to this release. Cheers!

SQL> oradebug help

或者

SQL> oradebug help [command]

比如：

SQL> oradebug help setmypid
SETMYPID                                 Debug current process

SQL语句跟踪（SQL statement tracing）

SQL> oradebug setmypid
Statement processed.
SQL> oradebug event 10046 trace name context forever, level 4
Statement processed.
SQL> select * from v$option where parameter = ‘Real Application Clusters’;

PARAMETER                                VALUE
—————————————- —–
Real Application Clusters                TRUE

SQL> oradebug tracefile_name
/ee/oracle/rac/admin/orcldb/udump/orcldb1_ora_2011322.trc
SQL> oradebug close_trace
Statement processed.

错误堆栈转储（Error stack dumping）

SQL> oradebug setmypid
Statement processed.
SQL> oradebug event 942 trace name errorstack level 3
Statement processed.
SQL> select * from abc;
select * from abc
*
ERROR at line 1:
ORA-00942: table or view does not exist

SQL> oradebug tracefile_name
/ee/oracle/rac/admin/orcldb/udump/orcldb1_ora_1253470.trc
SQL> oradebug close_trace
Statement processed.