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
2,513 reads
SQL Server internal storage
2025-05-16
628 reads
2025-01-15
1,863 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)
4,998 reads
Identify Tables With Dropped Columns
How easily can we find tables with dropped columns that need cleanup?
2024-06-07
2,599 reads
2024-04-10
462 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
8,796 reads
Understanding CRUD Operations Against Heaps and Forwarding Pointers
In this article, we examine how data changes are made against heaps.
2021-05-03
4,871 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
20,779 reads
2020-06-26
652 reads
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Partitioning a table with TEXTIMAGE_ON option
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OUTER APPLY Fundamentals: Part 2
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Building Great Software
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Question of the Day
The Range of Customers
I have this data in the OrderHeader table in a SQL Server 2025 database (ordered by CustomerID ASC):
orderid orderdate customerid complete 3 2025-05-10 00:00:00.0002 1 21 2024-01-10 00:00:00.0003 1 15 2023-10-28 00:00:00.0004 1 13 2025-03-08 00:00:00.0006 1 11 2024-04-02 00:00:00.0007 1If I run this query, how many rows are returned?
SELECT * from dbo.OrderHeader where customerid between 3 and '6'See possible answers