Performance Comparison: Comparing Column Differences

Shane O’Neill has a column difference showdown:

The original post for this topic garnered the attention of a commenter who pointed out that the same result could be gathered using a couple of UNION ALLs and those lovely set-based EXCEPT and INTERSECT keywords.

I personally think that both options work and whatever you feel comfortable with, use that.

It did play on my mind though of what the performance differences would be…what would the difference in STATISTICS IO, TIME be? What would the difference in Execution Plans be? Would there even be any difference between the two or are they the same thing? How come it’s always the things I tell myself not to forget that I end up forgetting?

This may not be the most important thing to test, but it does show you a technique.

Related Posts

Scoping And Powershell Script Blocks

Shane O’Neill looks at variable scope within script blocks in Powershell: Now what happens if we don’t want to use switch? What happens if we tried to do this with script blocks instead? I’ve created 3 different script blocks here just for ease of use. If you want to create a single script block to […]

Read More

VLFs: How Many Are Too Many?

Randolph West looks at a baseline for the maximum number of Virtual Log Files for a database: In a transaction log with too many or too few VLFs we might experience performance issues under a normal workload, as well as during the backup and restore process. So what is the “right” amount? In customer engagements, I follow a […]

Read More

Categories

June 2017
MTWTFSS
« May Jul »
 1234
567891011
12131415161718
19202122232425
2627282930