NOT EXISTS vs NOT IN
Continuing with the mini-series on query operators, I want to have a look at NOT EXISTS and NOT IN.
Just one...
2010-02-18
56,811 reads
SQL In The Wild
Getting here from there
Another month, another blog chain, this time started by Paul Randal. I got tagged by both Grant and Steve, on...
2010-01-21
406 reads
SQL Pass session evaluations
I finally got the last of my PASS Summit session evals and so, like someotherpeople, I thought I’d make them...
2010-01-13
579 reads
IN vs INNER JOIN
Often in forum threads discussing query performance I’ll see people recommending replacing an INNER JOIN with an IN (or recommending...
2010-01-12
21,739 reads
Are trivial plans cached?
It is sometimes said that trivial execution plans are not cached and queries that have such plans are compiled on...
2009-12-08
1,248 reads
The most optimal join type
What’s the best join type for a query? Should we aspire to seeing nested loop joins in all our queries?...
2009-11-24
988 reads
TechEd Online Interview
Back in August at TechEd Africa I did a TechEd Online interview with Frikkie Bosch. Frikkie’s the marketing manager for...
2009-09-30
1,477 reads
More on the MVP SQL Server book
If you buy from Manning directly today or tomorrow, there’s a 50% discount . Use the code pop0928 at the checkout....
2009-09-29
1,374 reads
MVP book is available for preorder
Last year a large number of MVPs (mostly SQL Server) got together to write a book with all proceeds going...
2009-09-28
571 reads
Why is CheckDB rolling back transactions?
I saw this one on a forum recently and it’s a fun question to look into.
When running CheckDB on an...
2009-09-24
622 reads
Blogs
The flight recorder: Replaying what an AI agent did on my SQL Server
By Arun Sirpal
“What exactly did it do on my server?” is the first question a DBA...
Announcements from the Microsoft Fabric Community Conference — Barcelona 2026
By James Serra
Microsoft shared a broad set of Fabric, Power BI, and SQL updates at FabCon...
Au Revoir for now
By Steve Jones
No, I’m not quitting or retiring. Just going on vacation, but I leave tonight...
Forums
Let's Talk Certifications
Comments posted to this topic are about the item Let's Talk Certifications
The Hidden Security Risks of Role Combination in SSAS Tabular
Comments posted to this topic are about the item The Hidden Security Risks of...
The Empty Aggregate
Comments posted to this topic are about the item The Empty Aggregate
Question of the Day
The Empty Aggregate
I have this table in a SQL Server 2025 database:
CREATE TABLE [dbo].[CustomerOrder] ( [OrderID] [int] NULL, [CustomerID] [int] NULL, [total] [money] NULL ) ON [PRIMARY] GOWhat is returned from this code? (answers are for the sum and then the count)
SELECT SUM(total) AS sum,
COUNT(total) AS count
FROM dbo.CustomerOrder;
See possible answers