This started as a conversation with a couple of DBA friends when we were playing with MONREPORT.DBSUMMARY. That’s a pretty nifty way to get a quick look at a number of performance parameters, AND to limit the time period covered by the report.… Read the restContinue reading »
Recently, I needed to do some SQL profiling – discovering exactly what SQL a web application was executing against the database. I learned a lot, and when I learn a lot, I try to share with my readers.
I went into this exercise with two major misconceptions:
- A statement event monitor would collect parameter marker values
- Event monitor table output would be well documented and easy to figure out
I had the first misconception proven wrong pretty immediately.… Read the restContinue reading »
One of the top SQL tips on many lists for developers of SQL is to avoid applying a function to the table data. I think of this as avoiding funcitons on the left of my comparison operator (=, !=, , <, etc) – though that’s a simplification that may not always be correct.… Read the restContinue reading »
This post is specific to DB2 9.7. In DB2 10.1 and above, Usage Lists would be a better way to handle this.
In the course of writing my recent developerWorks article on low-cardinality indexes and an associated presentation, I found that I have dozes of indexes with a cardinality of 1 that are also recently used.… Read the restContinue reading »