The new cardinality estimation guesses row counts differently from the old one. This post tests both on SQL Server 2025 with one query, shows three switches that choose the model, and gives a safe way to upgrade.
CE Feedback for Expressions in SQL Server 2025
Inspect CE feedback for expressions in SQL Server 2025, check compatibility and Query Store, and observe repeated execution evidence.
SQL SERVER – DMV to Identify Incremental Statistics – Performance improvements in SQL Server 2014 – Part 3
Part 3 of my series on SQL Server 2014 performance improvements: a DMV to identify incremental statistics, after the basics and a simple example.
SQL SERVER – Simple Example of Incremental Statistics – Performance improvements in SQL Server 2014 – Part 2
Part 2 of my series on SQL Server 2014 performance improvements: a simple example of incremental statistics, after learning what it is in part 1.
SQL SERVER – What is Incremental Statistics? – Performance improvements in SQL Server 2014 – Part 1
This is the first part of the series Incremental Statistics. Here is the index of the complete series. Let us learn it together in the blog.
Exponential Backoff: How SQL Server Estimates Several Filters
The plan guessed 89 rows and 500 came back. Here is the rule behind that guess, and what to do about it.
Reading DBCC SHOW_STATISTICS Step by Step
Read SHOW_STATISTICS headers, density and histogram boundaries, compare estimates with your plan, and query the histogram directly.