Customizing Statistics Histogram in SQL Server 2019

The use of statistics in SQL Server is tightly embedded in the query optimizer and query processor. The creation and maintenance of statistics is usually handled by the SQL Server engine, though many DBAs and developers know that periodically we might need to update those statistics to ensure good performance of queries. SQL Server 2019 gives us more options.

Auto Created Statistics

Finding & Fixing Statistics Without Histograms

Men Without Hats were awesome. Statistics without histograms are terrible, but now they're easy to find and fix.

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Introduction to Statistics

This article will give a brief overview of how statistics are generated, stored, and used in SQL Server.

Statistics in SQL: Student’s t-test

Many undergraduates have misunderstood the name 'Students' in the t-test to imply that it was designed as a simple test suitable for students. In fact it was William Sealy Gosset, an Englishman publishing under the pseudonym Student, who developed the t-test and t distribution in 1908, as a way of making confident predictions from small sample sizes of normally-distributed variables. As Gosset's employer was Guinness, the brewer, Phil Factor takes a sober view of calculating it in SQL.

Statistics in SQL: Simple Linear Regressions

Although linear regressions can get complicated, most jobs involving the plotting of a trendline are easy. Simple Linear Regression is handy for the SQL Programmer in making a prediction of a linear trend and giving a figure for the level probability for the prediction, and what is more, they are easy to do with the aggregation that is built into SQL.

Statistics in SQL: Kendall’s Tau rank correlation

Statistical calculations in SQL are often perfectly easy to do. SQL was designed to be a natural fit for calculating correlation, regression and variance on large quantities of data. It just isn't always immediately obvious how. In the second of a series of articles, Phil factor shows how calculating a non-parametric correlation via Kendall's Tau or Spearman's Rho can be stress-free.

Statistics in SQL: Pearson’s Correlation

Some people will assure you that you can't do any serious statistical calculations in SQL. In the first of a series of articles, Phil factor aims to prove them wrong by explaining how easy it is to calculate Pearson's Product Moment Correlation.

Can I Use Statistics to Design Indexes?

"I’ve noticed that many indexes in my data warehouse aren’t used frequently. Is there a way to use the automatically generated statistics to make useful indexes?"
Kendra Little answers the question in episode 18 of Dear SQL DBA.