SQL Window Functions Series: LAG() and LEAD()
Dive deep into the powerful SQL window functions, LAG() and LEAD(). Explore their intricacies, discover real-world examples, and avoid common pitfalls.
2023-12-11
9,581 reads
Dive deep into the powerful SQL window functions, LAG() and LEAD(). Explore their intricacies, discover real-world examples, and avoid common pitfalls.
2023-12-11
9,581 reads
In the final article of this series, Edward Pollack demonstrates the maintenance of columnstore indexes. He also takes a look at nonclustered columnstore and memory-optimized columnstore indexes.
2020-08-06
Because of its many roles, tempdb is the source of performance issues in SQL Server, and there are recommended configuration changes to mitigate this. In this article, Fabiano Amorim demonstrates another issue with tempdb performance that you probably didn’t know about.
2020-07-02
Table variables can cause performance issues with joins when they contain a large number of rows. In SQL Server 2019, Microsoft has improved how the optimizer works with table variables which can improve performance without making changes to your code. In this article, Greg Larsen explains how this feature works and if it really does make a difference.
2020-06-22
Microsoft has added a group of features called Intelligent Query Processing to SQL Server 2017 and 2019. In this article, Greg Larsen explains one of the features, Scalar UDF Inlining.
2020-03-02
Window functions are more intuitive and simpler in many cases than alternative SQL methods.
2013-12-02
8,775 reads
By Vinay Thakur
Continuing from Day 4 where we learned Encoder, Decoder, and Attention Mechanism, today we...
By Vinay Thakur
Continuing from Day 3 where we covered LLM models open/closed and their parameters, Today...
By Steve Jones
One of the nice things about Flyway Desktop is that it helps you manage...
I'm fairly certain I know the answer to this from digging into it yesterday,...
Hi Team, I am trying to refresh the Azure Synapse Dedicated pool from production...
hi everyone I am not sure how to write the query that will produce...
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