Tim Mitchell

Tim Mitchell is a business intelligence consultant, author, and trainer. He has been building data solutions for over 20 years, and is a 13-time recipient of the Microsoft Data Platform MVP award (2010-2022). He is the founder and principal data architect at Tyleris Data Solutions.

Tim has spoken at international and local events including the SQL PASS Summit, SQLBits, SQL Connections, along with dozens of tech fests, code camps, and SQL Saturday events. He is the author of the book The SSIS Catalog: Install, Manage, Secure, and Monitor your Enterprise ETL Infrastructure, coauthor of the book SSIS Design Patterns, and is a contributing author on the charity book project MVP Deep Dives Vol 2.

You can visit his website and blog at TimMitchell.net or follow him on Bluesky at https://bsky.app/profile/tmitch.net.
  • Interests: SQL Server, Data Warehousing, ETL, Data Architecture, Python, Dbt

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Blog Post

ETL Modularity

Imagine for a moment that you’ve built a software thing. In fact, we’ll call it Thing. You put a lot...

2016-07-18 (first published: )

2,087 reads

Blog Post

Bad Data Can Kill

Bad data can kill. Literally. I’m not talking about the impact of bad data on the bottom line of business,...

2016-05-31 (first published: )

1,954 reads

Blog Post

Refocus

Three years ago, I left the ranks of full-time employment to become an independent consultant. At the same time, I...

2016-05-04

458 reads

Blog Post

ETL Auditing

It happens far too often: Once an ETL process has been tested and executes successfully, there are no further checks...

2016-03-29 (first published: )

2,290 reads

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Blogs

AI: Blog a Day – Day 5: Notebooks, Hugging face models and Fine Tuning

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Continuing from Day 4 where we learned Encoder, Decoder, and Attention Mechanism, today we...

AI: Blog a Day – Day 4: Transformers – Encoder, Decoder, and Attention

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Continuing from Day 3 where we covered LLM models open/closed and their parameters, Today...

Flyway Tips: Multiple Projects

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One of the nice things about Flyway Desktop is that it helps you manage...

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Forums

Can an Azure App Service Managed Identity be used for SQL Login?

By jasona.work

I'm fairly certain I know the answer to this from digging into it yesterday,...

Azure Synapse database refresh

By Sreevathsa Mandli

Hi Team, I am trying to refresh the Azure Synapse Dedicated pool from production...

how to write this query?

By water490

hi everyone I am not sure how to write the query that will produce...

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Question of the Day

Fun with JSON I

I have some data in a table: 

CREATE TABLE #test_data
(
    id INT PRIMARY KEY,
    name VARCHAR(100),
    birth_date DATE
);

-- Step 2: Insert rows  
INSERT INTO #test_data
VALUES
(1, 'Olivia', '2025-01-05'),
(2, 'Emma', '2025-03-02'),
(3, 'Liam', '2025-11-15'),
(4, 'Noah', '2025-12-22');
If I run this query, how many rows are returned? 
SELECT *
FROM OPENJSON(
     (
         SELECT t.* FROM #test_data AS t FOR JSON PATH
     )
             ) t;

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