Comments on: SSIS – Using a checksum to determine if a row has changed

By: E Andrews

E Andrews — Fri, 02 Sep 2011 03:23:09 +0000

You need to be very careful using a Checksum. Things like this will yield the exact same checksum even though they are really changes:

FirstName LastName ZipCode
Bob Roger 12345
Roger Bob 12345

The Checksum method instead of a MERGE is beneficial in data warehousing projects, especially with SCD’s.

By: Sandeep Moturi

Sandeep Moturi — Tue, 23 Aug 2011 10:08:39 +0000

Do not use any checksum transformation built by some XYZ. Use checksum() function given by microsoft in sql server.In oledb source instead of selecting table or view select the sql query and write a query to generate checksum in the source transfromation itself and later to left outrer join with target using merger join. from that take only null values on target using condinal split.. this gives the changed records using set based opreation.. this is a very fast processing technique compared to row by row lookup operation.

By: pram

pram — Tue, 28 Jun 2011 13:00:13 +0000

Will the checksum transform be better than merge TSQL?

By: pram

pram — Tue, 28 Jun 2011 11:08:56 +0000

I am using merge TSQL to do the detla load.
Will the lookup transform be better than merge TSQL

By: Aira

Aira — Sun, 22 May 2011 03:16:08 +0000

Posts like this brithegn up my day. Thanks for taking the time.

By: Rama

Rama — Fri, 13 May 2011 02:27:02 +0000

How about showing step by step example with screen shots? God will bless you.

Thanks.

By: Kashan

Kashan — Tue, 25 Jan 2011 08:31:20 +0000

Will generated hash change,if there is any change in column sequence ?

By: CarryLiu

CarryLiu — Fri, 03 Dec 2010 05:01:42 +0000

I’m sincerely appreciate the author.This problem is the real one that I want to solve.And the author helps me.

By: Kelly Childers

Kelly Childers — Thu, 19 Aug 2010 14:34:39 +0000

When I am trying to configure the OLE DB command with the ? I am getting an error. Can you please provide further clarification as to how this should be configured?

By: Cedric De Vroey

Cedric De Vroey — Tue, 09 Mar 2010 12:15:54 +0000

Hi,

I’m a Consultant at Numius and just tried the code from Keith Martin. http://ssismhash.codeplex.com/

I can recommend it to anyone, very good code and does exactly what it should do. Good work!

kind regards,

Cedric De Vroey
Consultant

Numius NV – Better performance starts with insight