When Page Prefetching Takes a Back Seat – Exploring Trace Flag 652 in SQL Server
Learn how a trace flag affects SQL Server reading from disk and where this might be a useful thing for you to enable.
2025-09-24
2,465 reads
SQL Server internal storage
2025-05-16
622 reads
2025-01-15
1,860 reads
What happens when we drop a column on a SQL Server table? Where's my space?
You have dropped a column and wondering why you haven't recovered any space? Let's take a look.
2024-08-01 (first published: 2024-04-26)
4,764 reads
Identify Tables With Dropped Columns
How easily can we find tables with dropped columns that need cleanup?
2024-06-07
2,510 reads
2024-04-10
455 reads
Understanding CRUD Operations on Tables with B-tree Indexes, Page-splits, and Fragmentation
Introduction Every DML transaction reads the data before it makes any changes. Not only during a SELECT query, but when you run any DML statement, insert, update, or delete, SQL Server first fetches a bunch of pages into the buffer pool locating the desired rows and changes them while synchronously writing to the transaction log […]
2021-05-10
8,316 reads
Understanding CRUD Operations Against Heaps and Forwarding Pointers
In this article, we examine how data changes are made against heaps.
2021-05-03
4,829 reads
Understanding the Internals of a Data Page
In Part 1 of this series, we examine the structure of data pages and how your tables are stored on these pages.
2021-04-13
20,099 reads
2020-06-26
645 reads
Blogs
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...
What DevOps Look Like in Microsoft Fabric
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Microsoft Fabric (not to be confused with the more general term “fabric” in DevOps)...
Forums
Can an Azure App Service Managed Identity be used for SQL Login?
I'm fairly certain I know the answer to this from digging into it yesterday,...
Azure Synapse database refresh
Hi Team, I am trying to refresh the Azure Synapse Dedicated pool from production...
how to write this query?
hi everyone I am not sure how to write the query that will produce...
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