Learn how to create a SQL Server execution plan. This article explains the basics used in performance tuning, an important skill for DBA's and SQL developers alike.
2014-02-20
10,663 reads
Understanding execution plans is a good basic skill for all DBA's and SQL developers. Darren White gives us an overview of what execution plans are in SQL Server and how they are used.
2017-03-10 (first published: 2014-02-18)
30,961 reads
2013-12-23
1,831 reads
A short SQL Spackle article to fill in your knowledge of SQL Server. In this one, Jason Brimhall shows how to export execution plans when you ask for query tuning help.
2013-10-29
5,123 reads
If a query is performing poorly, and you can't understand why, then that query's execution plan will tell you not only what data set is coming back, but also what SQL Server did, and in what order, to get that data. It will reveal how the data was retrieved, and from which tables and indexes, what types of joins were used, at what point filtering, sorting and aggregation occurred, and a whole lot more. These details will often highlight the likely source of any problem.
2020-12-23 (first published: 2013-07-30)
119,575 reads
2013-06-13
1,843 reads
I’ve been working with execution plans quite a lot in SQL Server 2012. There are a number of changes, most of them associated with new or different functionality. I had not noticed anything really fundamental until recently. I’ve become a huge proponent of always checking the properties of the SELECT statement. There’s so much useful information in there about what’s happened with the plan generation in the optimizer (not low level stuff, but the big picture items) that you should always be checking it first as a fundamental part of your plan examinations.
2011-12-14
6,689 reads
This free book is brought to you by Red Gate Software and Simple Talk Publishing. Why my query is running slow? Why isn't my index getting used? In order to answer these questions, you have to ask the same return question in each case: have you looked at the execution plan? Grant Fritchey provides the only dedicated and detailed guide to this essential topic.
2011-07-11
6,178 reads
'Split, Sort & Collapse' is, happily, not a description of the intrepid Fabiano Amorim after his epic series of articles about the ShowPlan operators. With renewed stamina, Fabiano continues his mission to describe all the major operators by explaining the Trivial Plan and the power of unique indices.
2011-04-22
3,882 reads
Did you ever wonder how and why your indexes affect the performances of joins? Once you've read Fabiano Amorim's unforgettable explanation, you'll learn to love the MERGE operator, and plan your indexes so as to allow the Query Optimiser to use it.
2011-01-20
3,194 reads
It is Friday, the queries are running, and nobody is watching the bill. That...
By Steve Jones
Annabel retired from Redgate Software this week. Across most of my career at Redgate,...
By Tim Radney
As a SQL Server DBA with years of experience tuning production environments, I’ve seen...
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I set up a few users on my SQL Server 2022 instance.
CREATE LOGIN User1 WITH PASSWORD = 'Demo12#1' CREATE USER User1 FOR LOGIN User1 GO CREATE LOGIN User2 WITH PASSWORD = 'Demo12#2' CREATE USER User2 FOR LOGIN User2 GO CREATE LOGIN User3 WITH PASSWORD = 'Demo12#3' CREATE USER User3 FOR LOGIN User3 GOI then created a schema that one of them owned. Under this schema, I added a table with some data.
CREATE SCHEMA MySchema AUTHORIZATION User1
GO
CREATE TABLE Myschema.MyTable(myid INT)
GO
INSERT MySchema.MyTable
(
myid
)
VALUES
(1), (2), (3)
GO
SELECT * FROM MySchema.MyTable
GO
I granted rights and verified that User2 could access this table.
GRANT SELECT ON Myschema.MyTable TO User2 GO SETUSER 'USER2' GO SELECT * FROM MySchema.MyTable GOThis worked. Now, I move this schema to a new user.
ALTER AUTHORIZATION ON SCHEMA::Myschema TO User3; GOWhat happens with this code?
SETUSER 'USER2' GO SELECT * FROM MySchema.MyTable GOSee possible answers