Understanding UNION and UNION ALL in SQL Server
A short look at the differences in UNION and UNION ALL in a SELECT query.
2025-04-07
4,387 reads
UNION ALL
UNION vs. UNION ALL in SQL Server
Sometimes there is a need to combine data from multiple tables or views into one comprehensive dataset. This may be for like tables within the same database or maybe there is a need to combine like data across databases or even across servers. I have read about the UNION and UNION ALL commands, but how do these work and how do they differ?
2019-12-05
UNION ALL Optimization
Paul White digs into row goals as he explains some interesting and inconsistent behavior with UNION ALL queries in SQL Server.
2017-06-13
5,896 reads
Blogs
ISACA AI Material/Exam Prep Discount (May 18 – June 30, 2026)
By Brian Kelley
If you are considering any of the ISACA AI certs like the Advanced Artificial...
A Fabric solution can be very cost effective
By ChrisJenkins
Are you currently using Microsoft Fabric or considering migrating to it? If so, there...
Track SQL Server Configuration Changes Using the Error Log
By SQLPals
Track SQL Server Configuration Changes Using the Error Log If you...
Forums
We Are Eating Our Own Seed Corn
Comments posted to this topic are about the item We Are Eating Our Own...
Before Using AI with Business Data, Read This
Artificial intelligence tools are quickly becoming part of daily business operations, from document analysis...
Designing SQL Server ETL Pipelines That Don't Break at Scale
Comments posted to this topic are about the item Designing SQL Server ETL Pipelines...
Question of the Day
Detecting Deadlocks Quickly
In the Database Engine, when a deadlock is detected, what does the detection interval shrink to (in time)?
See possible answers