The chance of having both updates at the same time is VERY minim.
But if that happens then the user second sees a before image for the row is
updating prior of the first user committing.
When both users commits then they will both see the same data but data
entered by the second user and you can check this by LOGMINING the redo log
actively involved.


All the best,
Regis (Call me Chevalier Cathare if you want)

-----Original Message-----
From: Dipan [mailto:oracledba-ezmlmshield-x31272008.[Email address protected]

Sent: 31 May 2004 15:35
To: LazyDBA.com Discussion
Subject: FW: Oracle Corp Question

Hi All Genius,

Question asked in oracle corp. interview.

Two session is opened and both is going to run "UPDATE EMP SET ENAME
= 'JACK' WHERE EMPNO=123"

Both users had entered at a same time. Whose query is executed first?
Or how oracle will handles this scenario?

Regards,

Dipan Desai





--------
website: http://www.LazyDBA.com
Please don't reply to RTFM questions
Oracle documentation is here: http://tahiti.oracle.com
To unsubscribe: see http://www.lazydba.com/unsubscribe.html
To subscribe: send a blank email to oracledba-[Email address protected]
By using this list you agree to these
terms:http://www.lazydba.com/legal.html
*********************************************************************
This electronic transmission is strictly confidential and intended solely
for the addressee. It may contain information which is covered by legal,
professional or other privilege. If you are not the intended addressee,
you must not disclose, copy or take any action in reliance of this
transmission. If you have received this transmission in error,
please notify the sender as soon as possible.

This footnote also confirms that this message has been swept
for computer viruses.
**********************************************************************


Oracle LazyDBA home page