Doing FIRST and LAST aggregates in SQL Server 2005
Users of Microsoft Access may be familiar with the aggregation functions FIRST and LAST. Basically, what you want from these aggregates is to scan the tables in a sorted order. The first or last value...
View ArticleUtility functions: fn_convert_to_base and fn_nums
I will often use code to illustrate my points in this blog. Because data generation is a big part of these examples, I will take the chance to introduce a few functions that I find useful for that. I...
View ArticleGrade of the Steel: Introduction
There are a lot of things I want to say on this blog, so I do apologize in advance for jumping a bit between subjects. I will shortly write the next installment of my data modeling series – but before...
View ArticleSmall differences between SQL Server and PostgreSQL
In my copious amount of spare time , I am currently working with Gapminder to build a data warehouse. We are using PostgreSQL and Ruby Rails as the development platform. As I learn PostgreSQL, I am...
View ArticleLatch and Spinlock Papers Published on Microsoft
I am happy to announce that my team mates, Ewan Fairweather and Mike Ruthruff have published two excellent whitepapers on latch and spinlock diagnosis. You can find them here: SQL Server latch...
View ArticleThe Ascending Key Problem in Fact Tables –Part two: Stat Job!
In my last post I described a common problem with statistics in data warehouses. I also directed you to a trace flag that partially solves the problem. There is an issue with this trace flag: at the...
View ArticleImplementing MurmurHash and CRC for SQLCLR
As we saw in my previous post, the build in hash functions of SQL Server were either expensive with good distribution, or cheap, but with poor distribution. As a breath of fresh air, let us look at a...
View ArticleRunning Many Batch Statements in Parallel
When designing highly scalable architectures for modern machines, you will often need to do some form of manual parallelism control. Managing this is not always easy, but in this blog I will give you...
View ArticleTPC-H: Schema and Indexes
The TPC-H benchmark is often used a method for customers to evaluate data warehouse products to make purchasing decisions. Because it is such a crucial benchmark, it is important to understand the...
View Article