SELECT Hints, Tips, Tricks FROM Hugo Kornelis WHERE RDBMS = 'SQL Server'

Book review: SQL Server Transaction Log Management

Hugo Kornelis — Sat, 15 Jun 2013 12:20:00 GMT

It was an offer I could not resist. I was promised a free copy of one of the newest books from Red Gate Books , SQL Server Transaction Log Management (by Tony Davis and Gail Shaw ), with the caveat that I should write a review after reading it. Mind you,...(read more)

Jetzt geht’s los - speaking in Germany!

Hugo Kornelis — Sun, 09 Jun 2013 21:37:28 GMT

It feels just like yesterday that I went to Munich for the very first German edition of SQL Saturday – and it was a great event. An agenda that was packed with three tracks of great sessions, and lots of fun with the organization, attendees, and other...(read more)

Why does SQL Server not compress data on LOB pages?

Hugo Kornelis — Thu, 31 Jan 2013 09:08:03 GMT

Enabling compression on your database can save you a lot of space – but when you have a lot of varchar(max) or nvarchar(max) data, you may find the savings to be limited. This is because only data stored on the data and index pages is compressed, and...(read more)

Bleeding Edge 2012 – session material

Hugo Kornelis — Sat, 27 Oct 2012 10:46:00 GMT

As promised, here are the slide deck and demo code I used for my presentation at the Bleeding Edge 2012 conference in Laško, Slovenia. Okay, I promised to have them up by Tuesday or Wednesday at worst, and it is now Saturday – my apologies for the delay....(read more)

SQLRally Nordic 2012 – session material

Hugo Kornelis — Fri, 05 Oct 2012 16:49:00 GMT

As some of you might know, I have been to SQLRally Nordic 2012 in Copenhagen earlier this week. I was able to attend many interesting sessions, I had a great time catching up with old friends and meeting new people, and I was allowed to present a session...(read more)

T-SQL User-Defined Functions: the good, the bad, and the ugly (part 4)

Hugo Kornelis — Fri, 24 Aug 2012 21:07:00 GMT

Scalar user-defined functions are bad for performance. I already showed that for T-SQL scalar user-defined functions without and with data access, and for most CLR scalar user-defined functions without data access , and in this blog post I will show that...(read more)

Upcoming speaking engagements – want to meet me?

Hugo Kornelis — Thu, 23 Aug 2012 21:28:00 GMT

I have a very busy time ahead of me, with lots of travel, lots of speaking engagements, and hence lots of opportunity to meet and catch up with what has become known as the SQL Family. (An excellent term, by the way – it describes exactly how it has always...(read more)

T-SQL User-Defined Functions: the good, the bad, and the ugly (part 3)

Hugo Kornelis — Fri, 29 Jun 2012 18:44:00 GMT

I showed why T-SQL scalar user-defined functions are bad for performance in two previous posts. In this post, I will show that CLR scalar user-defined functions are bad as well (though not always quite as bad as T-SQL scalar user-defined functions). I...(read more)

T-SQL User-Defined Functions: the good, the bad, and the ugly (part 2)

Hugo Kornelis — Sat, 26 May 2012 14:56:00 GMT

In a previous blog post , I demonstrated just how much you can hurt your performance by encapsulating expressions and computations in a user-defined function (UDF). I focused on scalar functions that didn’t include any data access. In this post, I will...(read more)

T-SQL User-Defined Functions: the good, the bad, and the ugly (part 1)

Hugo Kornelis — Sun, 20 May 2012 14:08:00 GMT

So you thought that encapsulating code in user-defined functions for easy reuse is a good idea? Think again! SQL Server supports three types of user-defined functions. Only one of them qualifies as good. The other two – well, the title says it all, doesn’t...(read more)

Principles of Modeling: Avoid Redundancy

Hugo Kornelis — Sat, 05 May 2012 19:31:12 GMT

In 1994, I learned a method for data modeling that is based on three principles. I immediately knew that these principles should embraced by anyone who does any data modeling or process modeling. Or almost any other job, for that matter. I have described...(read more)

The Curious Case of the Optimizer that doesn’t

Hugo Kornelis — Thu, 03 May 2012 22:13:00 GMT

The optimizer is the part of SQL Server that takes your query and reorders and rearranges your query to find the optimal execution plan. In theory. In practice, that doesn’t always work out well. Often, the optimizer manages to come up with brilliant...(read more)

Slides and demo code for Columnstore Index session

Hugo Kornelis — Wed, 04 Apr 2012 20:58:00 GMT

Almost a week has passed after SQLBits X in London , so I guess it’s about time for me to share the slides and demo code of my session on columnstore indexes. After all, I promised people I would do that – especially when I found out that I had enough...(read more)

80% off for SQL Azure!

Hugo Kornelis — Sun, 01 Apr 2012 14:50:00 GMT

I have spent the last three days at SQLBits X in London – a truly great experience! There were lots of quality sessions, but I also enjoyed meeting new people and catching up with old friends. One of these friends (and I hope he’s still a friend after...(read more)

Busy months ahead

Hugo Kornelis — Thu, 16 Feb 2012 19:48:01 GMT

Almost two months have passed since my last blog post. And while it’s true that I’ve had (much) longer breaks, I do have a good reason now. All the time that I would normally at least in part spend on preparing new blog posts is now reserved for preparing...(read more)