Performance testing

External Article

The Performance of Traversing a SQL Hierarchy

  • Article

Dwain Camps shows that, depending on the size and characteristics of some hierarchical data, six different methods of traversal can each be the fastest at some point. He illustrates the danger in generalizing from just one set of test data, and that it's foolish to assume that just because SQL code looks neat, it will perform well.

2014-05-14

2,625 reads

Blogs

What DevOps Look Like in Microsoft Fabric

By

Microsoft Fabric (not to be confused with the more general term “fabric” in DevOps)...

T-SQL Tuesday #192: What career risks have you taken?

By

I’m honored to be hosting T-SQL Tuesday — edition #192. For those who may...

AI: Blog a Day – Day 3: LLM Models – Open Source vs Closed Source

By

Continuing from Day 2 , we learned introduction on Generative AI and Agentic AI,...

Read the latest Blogs

Forums

Ready to launch your next big game?

By maryelbert

Looking for a creative and experienced mobile game development company that brings your game...

how to write this query?

By water490

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

Rollback vs. Roll Forward

By Steve Jones - SSC Editor

Comments posted to this topic are about the item Rollback vs. Roll Forward

Visit the forum

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;

See possible answers