SSIS - insert new lines, update lines

Question

What is the “best” or recommended method for checking which row has been changed and which rows already exist? I found several articles, but I'm not sure if these methods are the best:

http://www.ssistalk.com/2007/03/09/ssis-using-a-checksum-to-determine-if-a-row-has-changed/
http://itssmee.wordpress.com/2010/10/03/ssis-insert-and-update-rows-in-a-table-based-on-the-contents-of-a-excel-file/
http://consultingblogs.emc.com/jamiethomson/archive/2006/09/12/SSIS_3A00_-Checking-if-a-row-exists-and-if-it-does_2C00_-has-it-changed.aspx

I need this for really large amounts of data from 25 databases

EDIT:

This article ... http://consultingblogs.emc.com/jamiethomson/archive/2006/09/12/SSIS_3A00_-Checking-if-a-row-exists-and-if-it-does_2C00_-has-it- changed.aspx ... how to add a part to update records? Am I using the OLE DB command or something else in this article I can’t see?

Answer 1

These links are best there. Phil and Jamie are very good at it. Your only real alternative is to load the entire table and use the MERGE T-SQL command to determine the differences.

Jamie Thomson's mail has three exits that end in All All Union, which really don't work on your final database. To be clear, one of those outputs that you can discard because it is the output "unchanged" (the one labeled as "Age" remains the same). One of them labeled “New Customers” is the one you are likely to type into OLE DB Destination. The one that is labeled “Age has changed” is the one you moved to the OLE DB command line conversion.

OLE DB command line conversion is now not working so fast. There are ways around this slowness, but a quick search should fix this problem for you.