One question that I have been asked a few times of late in regard to performance tuning SSIS data flows is this: Why isn’t the Merge Join output sorted (i.e.IsSorted=True)? This is a fair question. After all both of the Merge Join inputs are sorted, hence why wouldn’t the output be sorted as well? Well here’s a little secret, the Merge Join ...

It is pretty much accepted by SQL Server Integration Services (SSIS) developers that synchronous transformations are generally quicker than asynchronous transformations (for a description of synchronous and asynchronous transformations go read Asynchronous and synchronous data flow components). Notice I said “generally” and not “always”; there are ...