Wednesday, September 30, 2009

Setting up Change Data Capture in SQL Server 2008

Good article on "Setting up Change Data Capture in SQL Server 2008" by Tim Chapman, TechRepublic. As some of the commentators noted, the article explains how to easily setup CDC in SQL 2008, but provides no help for querying the CDC tables.

How to Calculate Data Warehouse Reliability

Very good article on "How to Calculate Data Warehouse Reliability" by Ashok Nayak. He makes the point that even if every stage in your data warehouse processing has 90%+ reliability, your DW as a whole might only have 70 or 80% reliability. Conventional thinking leads us to believe that every stage is like a link in a chain (where the chain is only as strong as its weakest link), but he concludes that it's much worse than that, that processes P1, P2, and P3, with independent reliabilities R1, R2, and R3, respectively, is not MIN(R1, R2, R3), but is actually R1 * R2 * R3.

Monday, September 28, 2009

T-SQL Challenge #14

T-SQL Challenge #14 is out. I've completed the challenge functionally, now I will tweak my solution to improve performance.

Friday, September 18, 2009

Books by Joe Celko

Excellent article by Wesley Brown that summarizes a bunch of books by the legendary Joe Celko. Don't know Joe? "He has participated on the ANSI X3H2 Database Standards Committee, and helped write the SQL-89 and SQL-92 standards. He is the author of seven books on SQL, and over 800 published articles on SQL and other database topics."

Wednesday, September 9, 2009

SQL Formatting

Here is a good article on the need to develop formatting standards for T-SQL code within an organization.

Thursday, September 3, 2009

TSQL Challenge #12

Click here to view my solution for TSQL Challenge #12, which involves identifying missing dates in a range, and propagating values for those missing dates.

Tuesday, September 1, 2009

TSQL Challenge #13 - Set-based solution

The set-based solution took me 3 or 4 times as long to develop as the cursor-based solution yesterday. I'm not sure if that's the nature of set-based development, my own learning curve, or both (like going from algebra to calculas). The set-based solution took a couple of interesting tricks to solve, which I will hold off publishing until after the deadline to the challenge.