data-konzept

'I’ve been working on tuning a query for the last week and I’ve had to make several changes to the query’s logic. I’m always a little nervous when making those types of changes so I try to do some careful testing before I even suggest the changes to the developers. Who presumably at that point will put the changes into the test environment and run their own tests.

One of the tests I like to run is to generate a fair amount of output (10-50k rows) from both the original and the new queries (if possible), store them into temporary (not temp) tables, and then compare the two tables.

There are lots of ways to do compare the contents and structure of two tables but all have pros and cons.'...

http://www.sqlservercentral.com/blogs/sqlstudies/2016/05/12/comparing-the-contents-of-two-tables/