I had a curious performance issue today. An inline table-valued function (iTVF) was performing poorly for some parameter sets, and quite fast for other parameter values. In short, this one is fast: This one is slow: Turns out SQL Server used a plan with a hash join in the fast query, and a nested loop […]
Tag: syndicated
Speaking at GroupBy Conference – Spring 2020
I’m excited to announce I’ll be speaking at the virtual GroupBy conference this year. Thanks everyone who voted! I’ll be speaking at the European day on May 12th at 10AM UTC. My submitted session with the most votes was: The modern Cloud Data Warehouse – Snowflake on Azure (you can find more information about this […]
Cool Stuff in Snowflake – Part 12: IS DISTINCT FROM
I’m doing a little series on some of the nice features/capabilities in Snowflake (the cloud data warehouse). In each part, I’ll highlight something that I think it’s interesting enough to share. It might be some SQL function that I’d really like to be in SQL Server, it might be something else. Often you want to check the […]
Switching between different Azure Data Factory environments
When working with Azure Data Factory, it’s possible you have multiple ADF environments. For example, you can have one for dev, one for test and one for production. Unfortunately, the functionality to switch between them is a bit hidden in the user interface. One might assume you could find it in the breadcrumbs in the […]
Reading a SharePoint List with Azure Logic App
Sometimes in life you have to do things you really don’t like to do. Such as extracting data from a SharePoint List. Usually I use SSIS and the OData source component for this task, as described in one of my most popular articles ever: Reading SharePoint Lists with Integration Services 2017 (I’m not kidding). However, […]
Quickly Editing Data in SSMS
WARNING: do not do this in production. A quick blog post on a SSMS trick: how to quickly edit data. Sometimes you directly want to manipulate data without having to write a SQL statement. For example, in the development environment you want to modify a value in a column to test out a scenario, or […]
SUMX returns incorrect results with duplicates
Okay, the title of this blog post could also have been “SUMX returns unexpected results with duplicates”. The results only seem incorrect because an incorrect assumption might have been made. Let’s dive into the issue with an example. The Problem Suppose we have employees entering timesheet data. An employee can work on multiple projects in […]
Cool Stuff in Snowflake – Part 11: RESULT_SCAN
I’m doing a little series on some of the nice features/capabilities in Snowflake (the cloud data warehouse). In each part, I’ll highlight something that I think it’s interesting enough to share. It might be some SQL function that I’d really like to be in SQL Server, it might be something else. This post builds upon part 6 […]
Cloudbrew 2019 – Slides
Cloudbrew 2019 is over and it was a great event. Great speakers and a big audience. Even in my session there were a lot of attendees, which I found a bit surprising, because at general tech events there tend to be less people in the data tracks. Not this time however, I nicely filled room […]
Book Review: T-SQL Window Functions by Itzik Ben-Gan
A couple of years back Itzik Ben-Gan (the T-SQL guru) wrote the book Microsoft SQL Server 2012 High-Performance T-SQL Using Window Functions. It’s has been one of my most favorite technical books (I included it in this list): it was really an eye-opener to how useful and powerful window functions can be. It teaches the […]