As I recently already wrote, I consider my leukemia diary closed now. And since today is exactly one year after my stem cell donation, I now officially have no restrictions on travel anymore. So let’s celebrate that by attending lots of in person events in the near future! SQLSaturday Austin My first trip is in... The post Lots of events appeared first on SQLServerFast ..read more

It’s February 2014, and it’s time to write a new T-SQL Tuesday post. Our host is Brent Ozar, and his chosen topic is the last ticket we closed. Well, sorry my friend. I’ve been ill. I have not been on active duty for well over a year now. And if you really think that I... The post T-SQL Tuesday 171 – The end of a diary? appeared first on SQLServerFast ..read more

In part twenty-eight of the plansplaining series, I’ll wrap up the six-part mini-series on window functions. After covering the basics, fast-track optimization, window frames ending at UNBOUNDED FOLLOWING, window frames specified with RANGE instead of ROWS, and LAG and LEAD, we will look at the LAST_VALUE and FIRST_VALUE analytical functions, and find that a function... The post Plansplaining part 28 – The curious case of the missing FIRST_VALUE function appeared first on SQLServerFast ..read more

Welcome to the new year! And welcome to my first T-SQL Tuesday contribution of 2024. Reitse Eskens is our host, and he invites us to think back of a project that failed or was abandoned, and reflect on lessons learned. I love learning from mistakes. I often say that it’s important to learn from mistakes,... The post T-SQL Tuesday 170 – Abandoned projects appeared first on SQLServerFast ..read more

This is part twenty-seven of the plansplaining series, and episode five in the mini-series on window functions. The previous parts covered the basics, fast-track optimization, window frames ending at UNBOUNDED FOLLOWING, and window frames specified with RANGE instead of ROWS. In this post, we will shift our attention to the LAG and LEAD functions. Two... The post Plansplaining part 27 – LAG and LEAD appeared first on SQLServerFast ..read more

This is part twenty-six of the plansplaining series. And already the fourth episode about window functions. The first of those posts covered basic window functions; the second post focused on fast-track optimization for running aggregates, and the third post explained how the optimizer works around the lack of execution plan support for UNBOUNDED FOLLOWING. But... The post Plansplaining part 26 – Windows with a ranged frame appeared first on SQLServerFast ..read more

It is December. And it is Tuesday. So I guess it’s time for T-SQL Tuesday again. Our host this month is Kay Sauter, and his seasonally inspired topic is to call out the gratitude that we often feel towards other, but fail to express. This is a very easy task for me. If you’re a... The post T-SQL Tuesday 169 – Thank you, community! appeared first on SQLServerFast ..read more

This is part twenty-five of the plansplaining series, and the third part that covers window functions. I have already explained how basic window functions work, with or without a window frame. When a window frame is present, a Window Spool operator will, for each row, return first that row, and then all rows that are... The post Plansplaining part 25 – Windows without upper bound appeared first on SQLServerFast ..read more

I have been working hard, the past months, to complete the next series of videos for the Execution Plan Video Training. The advanced level of block 3, Combining Data, is now ready. And from now until the end of the year, you can benefit from a nice pre-order discount. Advanced joins The basics of each... The post Execution Plan Video Training – pre-orders open appeared first on SQLServerFast ..read more

This is part twenty-four of the plansplaining series. In the previous part, I explained the execution plans for basic window functions, with and without a window frame. Especially the latter group performed quite poorly in the examples. So let’s now look at an optimization that SQL Server can apply to most cases, that prevents this... The post Plansplaining part 24 – Windows on the fast track appeared first on SQLServerFast ..read more