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
7,847 reads
SQL Performance
Hands-On with Columnstore Indexes: Part 3 Maintenance and Additional Options
In the final article of this series, Edward Pollack demonstrates the maintenance of columnstore indexes. He also takes a look at nonclustered columnstore and memory-optimized columnstore indexes.
2020-08-06
Tempdb – Here’s a Problem You Didn’t Know You Have
Because of its many roles, tempdb is the source of performance issues in SQL Server, and there are recommended configuration changes to mitigate this. In this article, Fabiano Amorim demonstrates another issue with tempdb performance that you probably didn’t know about.
2020-07-02
Improve Row Count Estimates for Table Variables without Changing Code
Table variables can cause performance issues with joins when they contain a large number of rows. In SQL Server 2019, Microsoft has improved how the optimizer works with table variables which can improve performance without making changes to your code. In this article, Greg Larsen explains how this feature works and if it really does make a difference.
2020-06-22
Get Your Scalar UDFs to Run Faster Without Code Changes
Microsoft has added a group of features called Intelligent Query Processing to SQL Server 2017 and 2019. In this article, Greg Larsen explains one of the features, Scalar UDF Inlining.
2020-03-02
High-Performance Transact-SQL with Window Functions
Window functions are more intuitive and simpler in many cases than alternative SQL methods.
2013-12-02
8,767 reads
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Question of the Day
Query Plan Regressions --
For the Question of the day, I am going to go deep, but try to be more clear, as I feel like I didn't give enough info last time, leading folks to guess the wrong answer... :) For today's question: You’re troubleshooting a performance issue on a critical stored procedure. You notice that a previously efficient query now performs a full table scan instead of an index seek. Upon investigating, you find that an NVARCHAR parameter is being compared to a VARCHAR column in the WHERE clause. What is the most likely cause of the query plan regression?
See possible answers