As a system admin, DBA, or a developer it is our job to root out performance problems quickly. The trouble is that there are so many things that can cause performance issues it can be difficult to know every possible root cause. This is especially true when the root cause lies somewhere outside your area … Read more
Yesterday I showed you some real world SQL joins and their associated diagrams. I also left as an exercise for the reader this question regarding a standard three table join: “explain why I could need 127 different diagrams” I had a few people guess the answer on Twitter and G+ as well as some emails. … Read more
I found a diagram recently that helped to explain the different types of JOIN syntax. Being the type person that enjoys the visualization of abstract concepts such as set theory this diagram spoke to me. Despite the diagram being well done something seemed slightly wrong about it. I thought about it for a while and then it … Read more
Recently I wrote about about five database design mistakes you don’t want to make. Those mistakes were focused on database design, but what about the design process itself? It is possible that you could have all intentions of a solid design only to be let down by your overall design process. Here are the five ways … Read more
I’ve had this script in my toolbox for a few years now. I didn’t create it initially, and I have no idea who did. This script helps you to identify duplicate indexes. Why is that important? I’m glad you asked, mostly because I’m tired of answering my own questions and it’s good to have someone … Read more
Application code, that’s what causes deadlocks. Well, perhaps a combination of application code on top of database design, and access patterns, and transaction isolation levels, and… OK, here’s the point I need to make clear: the database engine does not suddenly seize up and start deadlocking transactions arbitrarily because it is tired one day. No, certain … Read more
