Hugo Kornelis
@hugokornelis.bsky.social
Husband, father of two, loves SQL Server execution plans
November is Black Friday month!
Don't miss your chance to purchase access to the SQLServerFast Execution Plan Video Training with a whopping 50% discount! Offer runs until the end of the month.
#SQLServer
sqlserverfast.com/blog/hugo/20...
Don't miss your chance to purchase access to the SQLServerFast Execution Plan Video Training with a whopping 50% discount! Offer runs until the end of the month.
#SQLServer
sqlserverfast.com/blog/hugo/20...
Black Friday 2025 - SQLServerFast
It’s October. Almost time for the annual Black Friday tradition, where companies prove how large their regular margins are by giving deep discounts to all their customers. Since the margin on my SQLSe...
sqlserverfast.com
November 6, 2025 at 2:00 PM
November is Black Friday month!
Don't miss your chance to purchase access to the SQLServerFast Execution Plan Video Training with a whopping 50% discount! Offer runs until the end of the month.
#SQLServer
sqlserverfast.com/blog/hugo/20...
Don't miss your chance to purchase access to the SQLServerFast Execution Plan Video Training with a whopping 50% discount! Offer runs until the end of the month.
#SQLServer
sqlserverfast.com/blog/hugo/20...
A few hours late - but the SQLServerFast Black Friday sale has now officially started. Until the end of the month, purchase prices for all my training videos are slashed in half!
sqlserverfast.com/video
sqlserverfast.com/video
The SQLServerFast Execution Plan Video Training - SQLServerFast
You know that performance of database queries is critical to the success of any application. Customers leave if the website feels slow. Reports that take too long to render are not used, however usefu...
sqlserverfast.com
November 1, 2025 at 2:25 PM
A few hours late - but the SQLServerFast Black Friday sale has now officially started. Until the end of the month, purchase prices for all my training videos are slashed in half!
sqlserverfast.com/video
sqlserverfast.com/video
New blog post! In which I announce that I once more offer a 50% Black Friday discount on all SQLServerFast Execution Plan Training Videos, valid through the entire month of November!
sqlserverfast.com/blog/hugo/20...
sqlserverfast.com/blog/hugo/20...
Black Friday 2025 - SQLServerFast
It’s October. Almost time for the annual Black Friday tradition, where companies prove how large their regular margins are by giving deep discounts to all their customers. Since the margin on my SQLSe...
sqlserverfast.com
October 11, 2025 at 1:26 PM
New blog post! In which I announce that I once more offer a 50% Black Friday discount on all SQLServerFast Execution Plan Training Videos, valid through the entire month of November!
sqlserverfast.com/blog/hugo/20...
sqlserverfast.com/blog/hugo/20...
New blog post live! In part 3 of the deep dive into hash tables, I will show you how to use our knowledge of the structure of the hash table to identify hash collisions from looking at query results.
#SQLServer
sqlserverfast.com/blog/hugo/20...
#SQLServer
sqlserverfast.com/blog/hugo/20...
A deep dive into hash tables, part 3 - SQLServerFast
Welcome back! In the previous parts, I first showed how a Hash Match (Left Outer Join) can give insight in the order of data in a hash table, and then used that trick to obtain and verify some interes...
sqlserverfast.com
September 27, 2025 at 3:47 PM
New blog post live! In part 3 of the deep dive into hash tables, I will show you how to use our knowledge of the structure of the hash table to identify hash collisions from looking at query results.
#SQLServer
sqlserverfast.com/blog/hugo/20...
#SQLServer
sqlserverfast.com/blog/hugo/20...
Reposted by Hugo Kornelis
LAST CHANCE! Early bird expires today!
Learn about ordering, grouping, and segmenting in #SQLServer execution plans, in the latest part of the SQLServerFast Execution Plan Video Training. Over 2 hours and 40 minutes of content, with $10 off!
sqlserverfast.com/blog/hugo/20...
Learn about ordering, grouping, and segmenting in #SQLServer execution plans, in the latest part of the SQLServerFast Execution Plan Video Training. Over 2 hours and 40 minutes of content, with $10 off!
sqlserverfast.com/blog/hugo/20...
Video training update 2025 - SQLServerFast
There have not been any updates for the SQLServerFast Execution Plan Video Training for a long time. In fact, it’s already over one and a half year since the last set of videos was released! But that ...
sqlserverfast.com
September 15, 2025 at 3:20 PM
LAST CHANCE! Early bird expires today!
Learn about ordering, grouping, and segmenting in #SQLServer execution plans, in the latest part of the SQLServerFast Execution Plan Video Training. Over 2 hours and 40 minutes of content, with $10 off!
sqlserverfast.com/blog/hugo/20...
Learn about ordering, grouping, and segmenting in #SQLServer execution plans, in the latest part of the SQLServerFast Execution Plan Video Training. Over 2 hours and 40 minutes of content, with $10 off!
sqlserverfast.com/blog/hugo/20...
Learn about ordering, grouping, and segmenting in #SQLServer execution plans, in the latest set of videos in the SQLServerFast Execution Plan Video Training. Over 2 hours and 40 minutes of content, for just $89.95 (until September 15).
sqlserverfast.com/blog/hugo/20...
sqlserverfast.com/blog/hugo/20...
Video training update 2025 - SQLServerFast
There have not been any updates for the SQLServerFast Execution Plan Video Training for a long time. In fact, it’s already over one and a half year since the last set of videos was released! But that ...
sqlserverfast.com
September 13, 2025 at 12:55 PM
Learn about ordering, grouping, and segmenting in #SQLServer execution plans, in the latest set of videos in the SQLServerFast Execution Plan Video Training. Over 2 hours and 40 minutes of content, for just $89.95 (until September 15).
sqlserverfast.com/blog/hugo/20...
sqlserverfast.com/blog/hugo/20...
Learn about ordering, grouping, and segmenting in #SQLServer execution plans, in the latest set of videos in the SQLServerFast Execution Plan Video Training. Over 2 hours and 40 minutes of content, for just $89.95 (until September 15).
sqlserverfast.com/blog/hugo/20...
sqlserverfast.com/blog/hugo/20...
Video training update 2025 - SQLServerFast
There have not been any updates for the SQLServerFast Execution Plan Video Training for a long time. In fact, it’s already over one and a half year since the last set of videos was released! But that ...
sqlserverfast.com
September 8, 2025 at 12:28 PM
Learn about ordering, grouping, and segmenting in #SQLServer execution plans, in the latest set of videos in the SQLServerFast Execution Plan Video Training. Over 2 hours and 40 minutes of content, for just $89.95 (until September 15).
sqlserverfast.com/blog/hugo/20...
sqlserverfast.com/blog/hugo/20...
The long wait is finally over!
The basic level of block 6 of the SQLServerFast Execution Plan Video Training, on sorting, grouping, and segmenting, is now available!
Read all about it: sqlserverfast.com/blog/hugo/20...
And then hurry up and buy access. Early bird pricing lasts until September 15!
The basic level of block 6 of the SQLServerFast Execution Plan Video Training, on sorting, grouping, and segmenting, is now available!
Read all about it: sqlserverfast.com/blog/hugo/20...
And then hurry up and buy access. Early bird pricing lasts until September 15!
Video training update 2025 - SQLServerFast
There have not been any updates for the SQLServerFast Execution Plan Video Training for a long time. In fact, it’s already over one and a half year since the last set of videos was released! But that ...
sqlserverfast.com
September 6, 2025 at 3:11 PM
The long wait is finally over!
The basic level of block 6 of the SQLServerFast Execution Plan Video Training, on sorting, grouping, and segmenting, is now available!
Read all about it: sqlserverfast.com/blog/hugo/20...
And then hurry up and buy access. Early bird pricing lasts until September 15!
The basic level of block 6 of the SQLServerFast Execution Plan Video Training, on sorting, grouping, and segmenting, is now available!
Read all about it: sqlserverfast.com/blog/hugo/20...
And then hurry up and buy access. Early bird pricing lasts until September 15!
I just blogged: A deep dive into hash tables, part 2.
Do we need to know the internal structure of a hash table? Well, not really. Is it fun to figure it out anyway? Oh yeah!
sqlserverfast.com/blog/hugo/20...
Do we need to know the internal structure of a hash table? Well, not really. Is it fun to figure it out anyway? Oh yeah!
sqlserverfast.com/blog/hugo/20...
A deep dive into hash tables, part 2 - SQLServerFast
In part 1 of this series, I laid the foundation to explore the structure of the hash table, as used by the Hash Match operator, by alleging and then proving that a Hash Match (Left Outer Join) returns...
sqlserverfast.com
August 30, 2025 at 1:20 PM
I just blogged: A deep dive into hash tables, part 2.
Do we need to know the internal structure of a hash table? Well, not really. Is it fun to figure it out anyway? Oh yeah!
sqlserverfast.com/blog/hugo/20...
Do we need to know the internal structure of a hash table? Well, not really. Is it fun to figure it out anyway? Oh yeah!
sqlserverfast.com/blog/hugo/20...
It's been a long time since I last blogged. But today, I did!
Part 1 of a series that will probably be at least four parts, and where we'll be wasting our time to look into the internals of hash tables in #SQLServer. Geek out!
sqlserverfast.com/blog/hugo/20...
Part 1 of a series that will probably be at least four parts, and where we'll be wasting our time to look into the internals of hash tables in #SQLServer. Geek out!
sqlserverfast.com/blog/hugo/20...
A deep dive into hash tables, part 1 - SQLServerFast
We all know the Hash Match operator. It joins or aggregates data, based on a hash table. That hash table is ideally stored in memory. But if the granted memory is insufficient, then Hash Match will sp...
sqlserverfast.com
August 14, 2025 at 11:15 AM
It's been a long time since I last blogged. But today, I did!
Part 1 of a series that will probably be at least four parts, and where we'll be wasting our time to look into the internals of hash tables in #SQLServer. Geek out!
sqlserverfast.com/blog/hugo/20...
Part 1 of a series that will probably be at least four parts, and where we'll be wasting our time to look into the internals of hash tables in #SQLServer. Geek out!
sqlserverfast.com/blog/hugo/20...
I wrote a new page for the #SQLServer Execution Plan Reference. Two in fact. Both for the little known Put operator.
sqlserverfast.com/epr/put/
And, as always, a bunch of other updates too.
sqlserverfast.com/epr/change-l...
sqlserverfast.com/epr/put/
And, as always, a bunch of other updates too.
sqlserverfast.com/epr/change-l...
Put - SQLServerFast
Introduction The Put operator is used to insert data in external (Polybase) tables. This operator was introduced in SQL Server 2016. At that time, the only writeable Polybase target was Hadoop. That c...
sqlserverfast.com
August 4, 2025 at 1:09 PM
I wrote a new page for the #SQLServer Execution Plan Reference. Two in fact. Both for the little known Put operator.
sqlserverfast.com/epr/put/
And, as always, a bunch of other updates too.
sqlserverfast.com/epr/change-l...
sqlserverfast.com/epr/put/
And, as always, a bunch of other updates too.
sqlserverfast.com/epr/change-l...
A new update to the #SQLServer Execution Plan Reference!
* Added all the different names of the Result and Language Element operators to the list of all operators.
* Added a change log at the end of each page.
* Various other changes
sqlserverfast.com/epr/change-l...
* Added all the different names of the Result and Language Element operators to the list of all operators.
* Added a change log at the end of each page.
* Various other changes
sqlserverfast.com/epr/change-l...
Change log - SQLServerFast
This site has different types of readers. Those that come here to quickly look up something, using it as the reference this is. And those that read everything, or at least the pages they consider inte...
sqlserverfast.com
July 6, 2025 at 3:45 PM
A new update to the #SQLServer Execution Plan Reference!
* Added all the different names of the Result and Language Element operators to the list of all operators.
* Added a change log at the end of each page.
* Various other changes
sqlserverfast.com/epr/change-l...
* Added all the different names of the Result and Language Element operators to the list of all operators.
* Added a change log at the end of each page.
* Various other changes
sqlserverfast.com/epr/change-l...
When your laptop won't connect to the projector, and you have to present on a borrowed laptop ... which doesn't have your demo data ... and which uses Slovenian (??) Keyboard mapping.
#DataSatCroatia
/cc @DejanSarka
#DataSatCroatia
/cc @DejanSarka
a man in a green shirt is eating a sandwich with the words life on mars on the bottom right
Alt: Sheldon Cooper hyperventilating in a paper bag.
media.tenor.com
June 14, 2025 at 10:52 AM
When your laptop won't connect to the projector, and you have to present on a borrowed laptop ... which doesn't have your demo data ... and which uses Slovenian (??) Keyboard mapping.
#DataSatCroatia
/cc @DejanSarka
#DataSatCroatia
/cc @DejanSarka
I'm still not feeling well, but my voice recovered enough that I can at least start my presentation today. And, hopefully, make it until the end. Come see me at #sqlday, room A, 15:00, if you want to learn about approximate functions in #SQLServer.
May 14, 2025 at 10:53 AM
I'm still not feeling well, but my voice recovered enough that I can at least start my presentation today. And, hopefully, make it until the end. Come see me at #sqlday, room A, 15:00, if you want to learn about approximate functions in #SQLServer.
I'm very sorry to hear this.
Hopefully you'll find a great new opportunity soon.
Hopefully you'll find a great new opportunity soon.
May 14, 2025 at 6:08 AM
I'm very sorry to hear this.
Hopefully you'll find a great new opportunity soon.
Hopefully you'll find a great new opportunity soon.
Aanstaande vrijdag, zaterdag en zondag speelt amateur musical groep Jabber in Arnhem de voorstelling "Jackpot!". Zin in twee uurtjes vermaak? Zin om mij te zien zonder dat ik over execution plans praat? Er zijn nog kaarten!
www.jabbertheater.nl/winkel/
www.jabbertheater.nl/winkel/
Winkel | Welkom bij Jabber
www.jabbertheater.nl
May 6, 2025 at 11:00 AM
Aanstaande vrijdag, zaterdag en zondag speelt amateur musical groep Jabber in Arnhem de voorstelling "Jackpot!". Zin in twee uurtjes vermaak? Zin om mij te zien zonder dat ik over execution plans praat? Er zijn nog kaarten!
www.jabbertheater.nl/winkel/
www.jabbertheater.nl/winkel/
Op 9, 10, en 11 mei speelt musical vereniging Jabber in Arnhem onze jaarlijkse voorstelling. Dus, heb je zin in een uitje? Wil je mij eens zien en horen in een heel andere rol? Wees welkom!
www.jabbertheater.nl
www.jabbertheater.nl
Welkom bij Jabber!
De leukste musicalgroep van Arnhem
www.jabbertheater.nl
April 17, 2025 at 10:46 AM
Op 9, 10, en 11 mei speelt musical vereniging Jabber in Arnhem onze jaarlijkse voorstelling. Dus, heb je zin in een uitje? Wil je mij eens zien en horen in een heel andere rol? Wees welkom!
www.jabbertheater.nl
www.jabbertheater.nl
I just published a new page to the #SQLServer Execution Plan Reference. All the details about Remote Update.
sqlserverfast.com/epr/remote-u...
I also made several improvements on other pages.
sqlserverfast.com/epr/change-l...
sqlserverfast.com/epr/remote-u...
I also made several improvements on other pages.
sqlserverfast.com/epr/change-l...
Remote Update - SQLServerFast
Introduction The Remote Update operator updates rows in a table or view on a remote server. It reads rows from its child, one by one, and sends them to the remote server for updating. If an error is r...
sqlserverfast.com
March 6, 2025 at 1:43 PM
I just published a new page to the #SQLServer Execution Plan Reference. All the details about Remote Update.
sqlserverfast.com/epr/remote-u...
I also made several improvements on other pages.
sqlserverfast.com/epr/change-l...
sqlserverfast.com/epr/remote-u...
I also made several improvements on other pages.
sqlserverfast.com/epr/change-l...
I just uploaded the (final) part 11 of the video series "Database design made easy", where I talk about Domain-Key Normal Form. Come check it out!
www.youtube.com/watch?v=Tp1K...
www.youtube.com/watch?v=Tp1K...
Database design made easy, part 11: Domain-Key Normal Form
YouTube video by Hugo Kornelis
www.youtube.com
February 27, 2025 at 11:56 PM
I just uploaded the (final) part 11 of the video series "Database design made easy", where I talk about Domain-Key Normal Form. Come check it out!
www.youtube.com/watch?v=Tp1K...
www.youtube.com/watch?v=Tp1K...
I'm working on the captions for a video I recorded off the cuff, without a prepared script. As always when I do that, I am shocked at how many sentences I start with "so,".
February 27, 2025 at 1:02 PM
I'm working on the captions for a video I recorded off the cuff, without a prepared script. As always when I do that, I am shocked at how many sentences I start with "so,".
Reposted by Hugo Kornelis
There's a certain kind of stupidity, a weaponized, arrogant stupidity, that merely being exposed to it makes you stupider. This is that kind of stupidity and I'm sorry for exposing you to it but I just have to say that OF COURSE DATA CAN LIE EVERYONE WHO EVER TOOK A STATISTICS CLASS KNOWS THIS JFC
Johnson: "Elon's cracked the code. He's now inside these agencies. He's created these algorithms that are constantly crawling through the data & as he told me in his office, data doesn't lie. We're gonna be able to get the information. We're gonna be able to transform the way federal govt works."
February 24, 2025 at 6:25 PM
There's a certain kind of stupidity, a weaponized, arrogant stupidity, that merely being exposed to it makes you stupider. This is that kind of stupidity and I'm sorry for exposing you to it but I just have to say that OF COURSE DATA CAN LIE EVERYONE WHO EVER TOOK A STATISTICS CLASS KNOWS THIS JFC
I just added a new page to the #SQLServer Execution Plan Reference, with everything you ever wanted to know (and more) about the Remote Delete operator.
sqlserverfast.com/epr/remote-d...
sqlserverfast.com/epr/remote-d...
Remote Delete - SQLServerFast
Introduction The Remote Delete operator deletes rows from a table or view on a remote server. It reads rows from its child, one by one, and sends them to the remote server for inserting. If an error i...
sqlserverfast.com
February 24, 2025 at 11:31 AM
I just added a new page to the #SQLServer Execution Plan Reference, with everything you ever wanted to know (and more) about the Remote Delete operator.
sqlserverfast.com/epr/remote-d...
sqlserverfast.com/epr/remote-d...
This month's #tsql2sday contribution is about permissions. And how to make it at least a bit less complex.
sqlserverfast.com/blog/hugo/20...
sqlserverfast.com/blog/hugo/20...
T-SQL Tuesday 183 – Permission hell - SQLServerFast
The 183rd edition of T-SQL Tuesday is hosted by Steve Jones. He has picked everyone’s favorite (cough) topic: permissions, and how to manage them. I am lucky. With my specialization in query performan...
sqlserverfast.com
February 11, 2025 at 3:49 PM
This month's #tsql2sday contribution is about permissions. And how to make it at least a bit less complex.
sqlserverfast.com/blog/hugo/20...
sqlserverfast.com/blog/hugo/20...
#NotPregnant
I'm happy to say that I won't have to cancel Data Community Austria Day.
In the interest of your health, there won't be any hugs. Sorry. #Flu
I'm happy to say that I won't have to cancel Data Community Austria Day.
In the interest of your health, there won't be any hugs. Sorry. #Flu
January 23, 2025 at 4:20 PM
#NotPregnant
I'm happy to say that I won't have to cancel Data Community Austria Day.
In the interest of your health, there won't be any hugs. Sorry. #Flu
I'm happy to say that I won't have to cancel Data Community Austria Day.
In the interest of your health, there won't be any hugs. Sorry. #Flu