Understanding TIMESTAMP (ROWVERSION) in SQL Server: ASP Alliance

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Understanding TIMESTAMP (ROWVERSION) in SQL Server

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by Abhishek Kumar Singh
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TIMESTAMP vs. UNIQUEIDENTIFIER

In SQL Server we have one more data type called UNIQUEIDENTIFIER. This is also used frequently to track the changes in table as well as to program some security based features. The following are the differences between TIMESTAMP and UNIQUEIDENTIFIER.

· Size of TIMESTAMP value is 8 bytes whereas size of UNIQUEIDENTIFIER is 16 bytes.

· TIMESTAMP is not based on system date or time. However, UNIQUEIDENTIFIER value is based on the computer's MAC addresses and system date time.

· The purpose to TIMESTAMP is to track the operation in tables on the database level. The purpose of UNIQUEIDENTIFIER is to have a unique value assigned to a row (maybe as primary key). It remains unique in any system in the world.

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Title: Understanding TIMESTAMP (ROWVERSION) in SQL Server
Name: Stuart Steedman
Date: 1/26/2011 4:08:12 AM
Comment:
Thanks, Abhisheck. Good article. I can now see how the timestamp column could be used to reliably filter all new/changed records.

Stu

Title: Exact use of timestamp
Name: Anu
Date: 10/8/2010 7:01:33 AM
Comment:
please tell me when and why tp use timestamp.. Confused a lot..

Title: Mr
Name: tv Krishna Kanth
Date: 7/20/2010 7:33:53 AM
Comment:
To know the latest Timestamp in table you can write a query like "select @@dbts from tblName" .. Yes TimeStamp is datatype which is ofcourse not related to any date & time like data types. here dbtp means data base time stamp you can remember simply with this expansion.. When defining/using a timestamp in a table no need to declare its column name..But the rowversion would ask for the column name eventhough they both are similar in functionality as per my knowledge..

Title: Nonsense
Name: RIG
Date: 4/23/2010 6:43:30 AM
Comment:
"Wikipedia.org defines timestamp in very clear manner, as follows:

A timestamp is a sequence of characters, denoting the date and/or time at which a certain event occurred."

Right. But TIMESTAMP in MS SQL Server has nothing to do with date or time.

Title: excellent
Name: Jeetendra
Date: 4/16/2010 3:52:33 AM
Comment:
This is Excellent. Thanks.

Title: good
Name: saravanan
Date: 1/16/2010 2:20:08 AM
Comment:
good article

Title: timestamp problem
Name: arpizt
Date: 10/29/2009 9:35:55 PM
Comment:
"UPDATE table SET field = current_timestamp where (field=1)"
Error msg this field cannot been update.

Thanks.

Title: arpizt@gmail.com
Name: abhishek
Date: 10/28/2009 6:41:21 PM
Comment:
arpizt@gmail.com can you post your query here?

Title: timestamp problem
Name: arpizt@gmail.com
Date: 10/27/2009 5:53:58 AM
Comment:
Hi,

I try to run the insert sql, but got this error ("Column or expression 'PaymentDate' cannot be updated." Why? How to overcome this problem?

Title: Abhishek Your Time Stamp Aarticle too good
Name: Gbbs Mith
Date: 6/13/2009 5:02:18 AM
Comment:
The article is very good because it was justified clearly time and datetime data type. Hope more such article

Thanks

Title: Beginner
Name: nagarajan
Date: 3/17/2009 9:47:06 AM
Comment:
excellent artice about TIMESTAMP.

Title: good
Name: Jen
Date: 12/18/2008 4:57:37 AM
Comment:
good for quick walkthrough.