Sunday, May 20, 2007

Turn off Fn key - weird behavior of keyboard

You might be astonished by typing keys in the keyboards. You are typing "u" and it becomes "4", typing "i" becomes "5". Same is true for keys o,l,;,k,j,m,7,9,0,/,p. Pressing one key becomes another one. But if you hold down Fn key and type these keys then it appears correctly. If you look carefully at the keyboard you'll see that several keys include blue lettering themselves. In fact, if you look at the keys 7, 8, 9, 0 on the top row, U, I, O, P on the next, J, K, L, : on the next and M, > and ? on the bottom, you'll see that each has a blue character on it. These blue characters work whenever you press the key while hold down the Fn key.

Note that the Fn key (also known as the Function key) is a feature found on most laptop computers. The Fn key allows several other keys on a laptop's keyboard to serve more than one function. Within limited space it increases the functionality of typing more keys. Dell, Asus laptops make good use of the Fn key. So, if you have the keyboards with Fn key you should be familiar about how to use them.

Now the point is without holding your Fn keys you are getting keys as if you are pressing Fn key. And so you are searching remedy of this problem. Based on your keyboard you can get original settings of your keyboard in following ways.

1)Try Fn+F11 key combination.
2)Shift + Num Lock.
3)Fn+ Num Lock.
4)Fn+F11+Scroll lock
5)Fn + F8 (on HP laptop)

Now you might wonder where you will get Num Lock or Scroll Lock key. This is simple really. You can easily try the key combination by your On-Screen Keyboard. You can find it through
Start -> Programs -> Accessories -> Accessibility
Enjoy!

Saturday, May 5, 2007

Huge number of oracle processes and oracle is not releasing process

Problem Symptoms 

In the database there is huge number of Oracle database processes and within several hours the processes reached the max limit of PROCESSES parameter. No one then can connect to database and therefore it is needed to restart the Server or need to kill the oracle process from operating system.

Recent changes are the,
1)Enable DCD.
2)SQLNET.EXPIRE_TIME is set to 1 or more.

Cause of the Problem
This problem is specific with Oracle Database release 10.2.0.3 and on Windows Platform. It is due to the the DCD (dead connection detection) mechanism. The orphaned processes are not being cleaned up even though DCD is enabled and SQLNET.EXPIRE_TIME is set to 1 or more.

Also the number of processes exceeds too much than the number of sessions.
SQL> select count(*) from v$session;

COUNT(*)
----------
55

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

COUNT(*)
----------
600
In this case, the orphaned resources are not released if only the client application is terminated. After only the client computer has been rebooted, the DCD releases those resources. For example, a Windows application is killed but Windows machine remains running, the probe packet may be received and discarded as if the connection is still active. As it currently stands, it appears that DCD detects dead client machines, but not dead client processes.

Solution of the Problem
1. Comment the SQLNET.EXPIRE_TIME parameter in your sqlnet.ora file.
2. Reboot the server. Server reboot is funny thing to solve the problem.
3. Set KeepAlive mechanism in Windows 2000/NT.
To do so,
- Start > Run > Regedit.exe
- In the Registry, navigate to:
HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Tcpip/Parameters

- Edit - Add value: KeepAliveTime (REG_DWORD)
Decimal -> 180000 (for example = 3 minutes)

- The parameter will not be present the first time you modify the parameter, so you will need to add it. The default value is 2 hours.
4. Watch to see if there are any check if orphaned SHAD processes that exist.