Query Optimizer Suggests Wrong Index and Query Plan -- Why?
A good example where the Query optimizer picks the wrong query plan and suggested index.
2021-02-25
4,194 reads
A good example where the Query optimizer picks the wrong query plan and suggested index.
2021-02-25
4,194 reads
Want to 'trick' SQL Server into performing millions of logical reads to return data, when only are few thousand were really required? In this article, Gail Shaw examines three common forms of generic SQL that can and will confuse the SQL Server Optimizer to the point that it generates and reuses very inefficient execution plans.
2015-09-21
3,875 reads
SQL Server Query Optimizer uses statistical information to estimate the cardinality in a query result. This enables the SQL Server Query Optimizer to create a high-quality query execution plan. Read on to learn how to use statistics and why it’s needed.
2015-01-07
8,382 reads
2013-09-19
2,854 reads
In this article, you will learn what query optimisation statistics are and how SQL Server query optimizer uses statistics. You will also learn how to create and manage statistics, and what are the different ways to determine when statistics were last updated in SQL Server.
2013-07-10
4,410 reads
To understand how to write SQL code for SQL Server that performs well, it is important to appreciate how the query optimizer works. Ben Nevarez explains the essentials, in a broad sweep through a complex subject, in an article taken from his new book 'Inside the SQL Server Query Optimizer'.
2011-09-09
4,876 reads
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