Titlebook: SQL Server 2022 Query Performance Tuning; Troubleshoot and Opt Grant Fritchey Book 2022Latest edition Grant Fritchey 2022 Performance Optim

他日关税重重

Statistics, Data Distribution, and Cardinality,’t count all the rows ahead of time, it maintains information about the distribution of data within a column. That information is called statistics. Statistics are used to establish estimates on row counts for the optimizer so that it can make better choices.

Schlemms-Canal

Query Recompilation,ave been updated, or something has happened so a different execution plan may enhance performance. Sometimes, this is a bad thing, and you get a lot of recompiles, placing excessive load on the processor and interfering with the general good behavior of queries on the system. This chapter covers the following topics:

concise

Query Design Analysis,ueries attempting to work on your data in a row-by-row fashion (quoting Jeff Moden, Row By Agonizing Row, abbreviated to RBAR). Focusing on fixing your T-SQL can be the single most important thing you can do to enhance the performance of your databases.

轻浮思想

Row-by-Row Processing from Cursors and Other Causes,cessing “ree-bar”, abbreviated as RBAR, standing for “Row By Agonizing Row” to point out just how slow it can be. However, there is sometimes a valid purpose behind cursors, so it’s best to try to use them the right way.

insightful

Ballerina

DOSE

Using Query Store for Query Performance and Execution Plans, so that you can see how plans and behaviors change over time. Then, it gives you the ability to control execution plans through a mechanism called plan forcing and another through query hints. All these taken together make the Query Store a very powerful tool for tuning queries.

缩减了

Index Architecture,mnstore index was introduced. Today, we actually get to pick our best storage mechanism for the data, whether a Clustered Rowstore or a Clustered Columnstore index, for the most common data access. Then we can add additional indexes to each to assist other query paths to the data.

侵害

全能

Blocking and Blocked Processes, the number of users on your systems increases, performance degrades as they contend for those resources. In order to understand how to deal with blocking, you need to understand how, and why, locking occurs.