SQL Window Functions Series: LAG() and LEAD()
Dive deep into the powerful SQL window functions, LAG() and LEAD(). Explore their intricacies, discover real-world examples, and avoid common pitfalls.
2023-12-11
11,276 reads
Performance Tuning
Analyze and Tune SQL Server Statistics
Over the years, SQL Server Statistics have been discussed in countless blog posts, articles, and presentations, and I believe that they will remain a core topic for a while when speaking about performance. Why is that?
2023-10-04
SQL Server Execution Plan Issues when using TOP Clause and Various Parameters
A query is sometimes super fast and sometimes very slow. One of the main reasons for this problem is Parameter Sniffing. There are several approaches to addressing the Parameter Sniffing issue and this article discusses effective methods for handling Parameter Sniffing in SELECT statements containing a TOP clause.
2023-09-18
Comparing Two Execution Plans
This is a short look at a technique that I discovered recently in Management Studio (SSMS). The technique is to compare two graphical execution plans in the tool to understand what they are doing and how two different queries might affect a particular system, both with the image and with the properties' data behind the […]
2023-11-24 (first published: 2021-03-30)
11,146 reads
SQL Server SET STATISTICS IO ON Deep Dive
In this article we look at how to interpret and use the results of STATISTICS IO when tuning SQL Server queries.
2021-02-17
Digging Into Internals
There are plenty of experts that look to teach you about query tuning and the internals of query execution in SQL Server.
2020-07-18
172 reads
A simple use case for Columnstore Indexes in SQL Server
In this article we look at different use cases for columnstore indexes like when performing SQL Server count * queries.
2020-01-17
Optimize Your SQL by Reformulating the Spec
As SQL developers, we tend to think of performance tuning in terms of crafting the best table indices, avoiding scalar and table valued functions, and analyzing query plans (among other things). But sometimes going back to the spec and applying some properties of elementary math can be the best way to begin to improve performance of SQL queries which implement mathematical formulas. This article is a case study of how I used this technique to optimize my SQL implementation of the Inverse Simpson Index.
2021-05-07 (first published: 2019-09-12)
5,439 reads
The Basics - Level 1 of the Stairway to Query Store
Introduction Instead of going straight into the topic of the Query Store, I would like to start this Stairway Series by mentioning a few performance tuning scenarios that are very common to production DBAs. I think most of us have been in one of these situations at some time: An application experiencing slowness after a […]
2020-10-07 (first published: 2019-05-13)
7,022 reads
IGNORE_DUP_KEY slower on clustered indexes
The IGNORE_DUP_KEY option for unique indexes specifies how SQL Server responds to an attempt to INSERT duplicate values: It only applies to tables (not views) and only to inserts. Any insert portion of a MERGE statement ignores any IGNORE_DUP_KEY index setting.
2019-04-05
Blogs
From DBA or Data Engineer to AI Engineer: A Realistic Path
If you spend your days tuning queries, managing pipelines, or keeping a production database...
Asynchronous Replication of Snapshots from an ActiveCluster Pod to a Third Array
I’ve been rebuilding my three-site SQL Server demo lab, and I ran into something...
SQL Server gMSA: Why So Many DBAs Still Aren't Using It in 2026
By SQLPals
SQL Server gMSA: Why DBAs Still Aren't Using It in 2026 ...
Forums
Never is Not the Policy
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Automating SSAS Multidimensional Security Audits with PowerShell
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Rebuilding All Indexes
Comments posted to this topic are about the item Rebuilding All Indexes
Question of the Day
Rebuilding All Indexes
I have added a few indexes to one of my tables in SQL Server 2025:
ALTER TABLE dbo.CustomerContact
ADD CONSTRAINT PK_CustomerContact
PRIMARY KEY (CustomerID);
-- Create index on CustomerEmail
CREATE INDEX IX_CustomerContact_CustomerEmail
ON dbo.CustomerContact (CustomerEmail);
CREATE INDEX IX_CustomerContact_CustomerEmail
ON dbo.CustomerContact (phone);
I then do this to disable one index:
alter index IX_CustomerContact_CustomerPhone on dbo.CustomerContact disableI see this when I check the index status:
I decide to rebuild all indexes with this command:
ALTER INDEX ALL ON dbo.CustomerContactAfter I do this, what will I see for the index status? See possible answers