Klaus Aschenbrenner
@sqlpassion.at
CEO & Founder of https://SQLpassion.at. SQL Server & PostgreSQL specialist during the day. Astrophotographer during the night. Triathlete in between. Loves low-level system programming in Rust.
When you create an ordered Non-Clustered Columnstore Index in SQL Server 2025, you need to do it single-threaded (MAXDOP = 1) to get a perfectly working Segment Elimination. The same also applies to Ordered Clustered Columnstore Indexes... #sqlserver #columnstore
November 17, 2025 at 11:53 AM
When you create an ordered Non-Clustered Columnstore Index in SQL Server 2025, you need to do it single-threaded (MAXDOP = 1) to get a perfectly working Segment Elimination. The same also applies to Ordered Clustered Columnstore Indexes... #sqlserver #columnstore
A simple comparison across the various backup compression algorithms in SQL Server 2025 (230 GB database backup on a 8 vCore VM, 16 GB RAM on Proxmox):
MS_XPRESS: 305 sec => 58 GB
ZSTD LOW: 203 sec => 50 GB
ZSTD MEDIUM: 310 sec => 44 GB
ZSTD HIGH: 936 sec => 41 GB
MS_XPRESS: 305 sec => 58 GB
ZSTD LOW: 203 sec => 50 GB
ZSTD MEDIUM: 310 sec => 44 GB
ZSTD HIGH: 936 sec => 41 GB
November 15, 2025 at 3:02 PM
A simple comparison across the various backup compression algorithms in SQL Server 2025 (230 GB database backup on a 8 vCore VM, 16 GB RAM on Proxmox):
MS_XPRESS: 305 sec => 58 GB
ZSTD LOW: 203 sec => 50 GB
ZSTD MEDIUM: 310 sec => 44 GB
ZSTD HIGH: 936 sec => 41 GB
MS_XPRESS: 305 sec => 58 GB
ZSTD LOW: 203 sec => 50 GB
ZSTD MEDIUM: 310 sec => 44 GB
ZSTD HIGH: 936 sec => 41 GB
When you create a 230 GB database in SQL Server 2025, just to be able to demonstrate ZSTD backup compression more seriously... #sqlserver
November 15, 2025 at 1:58 PM
When you create a 230 GB database in SQL Server 2025, just to be able to demonstrate ZSTD backup compression more seriously... #sqlserver
The whole story about JSON indexes in SQL Server 2025 is just a big, late Aprils fool. @brento.bsky.social has summarized it quite well in his blog posting: www.brentozar.com/archive/2025....
And I'm getting even worser execution plans with my test data...
And I'm getting even worser execution plans with my test data...
November 14, 2025 at 9:16 PM
The whole story about JSON indexes in SQL Server 2025 is just a big, late Aprils fool. @brento.bsky.social has summarized it quite well in his blog posting: www.brentozar.com/archive/2025....
And I'm getting even worser execution plans with my test data...
And I'm getting even worser execution plans with my test data...
Final preparations for my upcoming webcast about #PostgreSQL tomorrow morning. There is still time to sign-up: www.sqlpassion.at/archive/2025...
November 11, 2025 at 12:38 PM
Final preparations for my upcoming webcast about #PostgreSQL tomorrow morning. There is still time to sign-up: www.sqlpassion.at/archive/2025...
November 6, 2025 at 2:23 PM
Calling the Azure OpenAI service directly from SQL Server 2025 to generate query embeddings, which will used afterwards for performing a vector search.
#SQLServer #Azure #OpenAI #LLM
#SQLServer #Azure #OpenAI #LLM
November 5, 2025 at 2:04 PM
Calling the Azure OpenAI service directly from SQL Server 2025 to generate query embeddings, which will used afterwards for performing a vector search.
#SQLServer #Azure #OpenAI #LLM
#SQLServer #Azure #OpenAI #LLM
Vector search in SQL Server 2025 is quite powerful. But the creation of the embeddings burns down *a lot* of energy. My RTX 3080Ti GPU was getting quite hot over the night. Thanks again to @sqlbek.bsky.social for his ready-to-use recipes database, which is available on github.com/SQLBek/Demo-....
November 5, 2025 at 10:54 AM
Vector search in SQL Server 2025 is quite powerful. But the creation of the embeddings burns down *a lot* of energy. My RTX 3080Ti GPU was getting quite hot over the night. Thanks again to @sqlbek.bsky.social for his ready-to-use recipes database, which is available on github.com/SQLBek/Demo-....
And I'm also burning down some GPU cycles on Mac OS ;-)
November 3, 2025 at 11:15 PM
And I'm also burning down some GPU cycles on Mac OS ;-)
Generating Embeddings for SQL Server 2025 through Ollama on my Windows machine. #sqlserver #sqlserver2025 #llm #ollama
November 3, 2025 at 10:58 PM
Generating Embeddings for SQL Server 2025 through Ollama on my Windows machine. #sqlserver #sqlserver2025 #llm #ollama
One quick question: you are referencing here in your INSERT statement columns, which are not part of the table definition? github.com/SQLBek/Demo-...
November 3, 2025 at 10:53 PM
One quick question: you are referencing here in your INSERT statement columns, which are not part of the table definition? github.com/SQLBek/Demo-...
I have just connected my Ollama REST endpoint that runs on Mac OS to SQL Server 2025. The tricky part was to use a reverse proxy on Mac OS (caddy) to forward the incoming https requests to the http only endpoint of Ollama.
#sqlserver #sqlserver2025 ##lm #ollama
#sqlserver #sqlserver2025 ##lm #ollama
November 3, 2025 at 5:31 PM
I have just connected my Ollama REST endpoint that runs on Mac OS to SQL Server 2025. The tricky part was to use a reverse proxy on Mac OS (caddy) to forward the incoming https requests to the http only endpoint of Ollama.
#sqlserver #sqlserver2025 ##lm #ollama
#sqlserver #sqlserver2025 ##lm #ollama
It‘s been a long time… #2048
November 2, 2025 at 6:40 PM
It‘s been a long time… #2048
Based on a single sys-prepped Windows Server image (2022, 2025), I can create now in a fully automated way (with #Terraform & #Ansible) in about 15 - 20 minutes a complete Windows Active Directory infrastructure, with running SQL Server instances, and a fully working Availability Group deployment.
October 31, 2025 at 10:45 PM
Based on a single sys-prepped Windows Server image (2022, 2025), I can create now in a fully automated way (with #Terraform & #Ansible) in about 15 - 20 minutes a complete Windows Active Directory infrastructure, with running SQL Server instances, and a fully working Availability Group deployment.
Integrating DbaTools into my Ansible playbook that installs SQL Server. I think @funbucket.dev likes it :-)
October 23, 2025 at 8:59 PM
Integrating DbaTools into my Ansible playbook that installs SQL Server. I think @funbucket.dev likes it :-)
Automatic installation of 6 SQL Server instances across 3 different operating systems (Windows, Linux Ubuntu, Linux RHEL) in only 20 minutes :-) #ansible
October 22, 2025 at 5:19 PM
Automatic installation of 6 SQL Server instances across 3 different operating systems (Windows, Linux Ubuntu, Linux RHEL) in only 20 minutes :-) #ansible
That's a nice one, but it has some issues with comment lines in yml files ;-)
October 21, 2025 at 7:22 PM
That's a nice one, but it has some issues with comment lines in yml files ;-)
Ansible rocks!!! I'm now deploying and configuring my *whole* VM infrastructure with a single Ansible playbook. It creates a Windows DC, joins Windows VMs into the domain, installs SQL Server 2025 RC1, and also installs SQL Server and PostgreSQL on Linux (Ubuntu 22.04/24.04, RHEL 9.6/10.0).
October 20, 2025 at 9:23 PM
Ansible rocks!!! I'm now deploying and configuring my *whole* VM infrastructure with a single Ansible playbook. It creates a Windows DC, joins Windows VMs into the domain, installs SQL Server 2025 RC1, and also installs SQL Server and PostgreSQL on Linux (Ubuntu 22.04/24.04, RHEL 9.6/10.0).
Having some 10Gbit fun between client devices - Windows 11 and a Mac Book Air 🙂
October 19, 2025 at 7:06 PM
Having some 10Gbit fun between client devices - Windows 11 and a Mac Book Air 🙂
October 19, 2025 at 6:16 PM
Some new 10Gbit networking hardware has arrived: a 10G edge switch for the office, and a Thunderbolt 10G netword adapter for the MacBook Air 🤗
October 19, 2025 at 2:15 PM
Some new 10Gbit networking hardware has arrived: a 10G edge switch for the office, and a Thunderbolt 10G netword adapter for the MacBook Air 🤗
Today I have achieved a lifetime goal: playing a game on Linux 💪
October 16, 2025 at 5:51 PM
Today I have achieved a lifetime goal: playing a game on Linux 💪
And now I can already run Ansible playbooks against deployed Windows VMs :-)
October 16, 2025 at 4:58 PM
And now I can already run Ansible playbooks against deployed Windows VMs :-)
