In this post, we will continue to look at the cardinality estimation changes in SQL Server 2016. This time we will talk about scalar UDF estimation. Scalar UDFs (sUDF) in SQL Server have quite bad performance and I encourage you try to avoid them in general, however, a lot of systems still use them.
Tag Archives: cardinality
Ascending Key and CE Model Variation
In this note I’m going to discuss the one of the most useful and helpful cardinality estimator enhancements – the Ascending Key estimation.
Overpopulated Primary Key and CE Model Variation
In this blog post we are going to talk about another cardinality estimation model enhancement in SQL Server 2014 – Overpopulated Primary Key (OPK).
Filtered Stats and CE Model Variation
In this blog post we are going to view some interesting model variation, that I’ve found while exploring the new CE.
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Cardinality Estimation Framework Version Control
This is a small post about how you may control the cardinality estimator version and determine which version was used to build a plan.
I don’t like re-writes, and this post is a complete re-write of the documentation. However, I decided to write it for the complete picture in my cardinality estimation series. Feel free to skip it, nothing really new here, if you are familiar with the theme from the other sources.
Cardinality Estimation Process
In this post we are going to take a deeper look at the cardinality estimation process. We will use SQL Server 2014, the main concepts might also be applied to the earlier versions, however the process details are different.
Cardinality Estimation Concepts
In this blog post we are going to talk about the principles and the main concepts which are used by the optimizer to perform an estimation.
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Cardinality Estimation Place in the Optimization Process
In this blog post, I’m going to look at the place of the Cardinality Estimation Process in the whole Optimization Process. We’ll see some internals, that will show us, why the Query Optimizer is so sensitive to the cardinality estimation. To understand that we should observe the main steps that a server performs when the query is sent for execution.
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Cardinality Estimation Role
This post opens a series of blog posts dedicated to my observations of the new cardinality estimator in SQL Server 2014. But, before we jump to the new features, I’d like to provide some background, to make the next posts clearer.
We’ll start by discussing the role of Cardinality Estimation in SQL Server, trying to answer – what is it and why it is needed.