Tampa SQL BI User Group – Designing Slowly Changing Dimensions
So Monday night was the monthly SQL BI user group meeting. Attending these meetings is always interesting for me since I’m not a BI-guy (leave out the gutter jokes please…) so I definitely learn something new. I also leave with a raging headache since I have trouble wrapping my head around some of this crazy stuff. I tip my hat off to you guys that specialize on the BI side of SQL Server. I’ve come to realize that its kind of like Texas Hold ‘Em poker vs Omaha. When it comes to SQL we’re all playing the same game with very different rules. Anyhow, I digress, back to the recap.
We started off with a general “what’s going on” discussion in the world of tech/SQL/etc. We talked about some of the big stuff that happened that day such as Microsoft’s numerous announcements during their E3 presentation, the public launch of Microsoft’s new search engine: Bing, the current state of job market (looking better, contact Stever Turner as he has quite a few SQL jobs available), Microsoft’s Second Shot offer (expires at the end of this month), next month’s SQL User Group meeting (I’ll be presenting on Policy Based Management), and the announcements regarding SQL Server 2008 R2 and “Gemini”, which turned out to be a very hot topic for the night! For the record our group is looking for more info and demos on Gemini so if you’re available for a talk and want to visit sunny Tampa drop Rob Hatton a line!
Speaking of Rob, he was our featured presenter this month on the topic of Designing Slowly Changing Dimensions. The discussion was based around the Kimball Methodology which if you’re not familiar with then you are highly encouraged to go grab a copy of The Data Warehouse Toolkit by Ralph Kimball. On the whole I found the presentation really good but after awhile some of the concepts start flying over my head.Some things I did walk with is that when you’re doing a data warehouse project some things you need to realize is that 80% of your effort will go towards the ETL, 5-10% to the cube and the remaining to the relational stuff. Another little tidbit I picked up is that apparently 3/4 of the source data that the BI pros in the room have dealt with to load into the staging portion of the DW are CSV/txt files which surprised me. Then again I’m a DBA so I believe everything should live in nice relational databases! I don’t mean to skimp on the details of the presentation mostly because I wouldn’t do it justice and I’d probably be wrong about the details. Rob’s slide deck should be available on the user group’s website soon and when it is I’ll link it here.
As an added bonus, and due to our lengthy discussion and excitement about SQL 2008 R2 and “Project Gemini”, Robert Skoglund from Microsoft, managed to show us a quick 6 minute video clip from Donald Farmer’s presentation on Gemini. Unfortunately it was without audio so we couldn’t get detailed explanations of the features. If you’re curious about Gemini check out this link from Donald Farmer’s blog that has everything you need to know.