SQL Server Performance Blog where milliseconds matter

Hi guys, Welcome back!   If you missed the first part of this post well click here ! We have seen the physical structure of an index and have talked about Singleton lookup and Range Scan .   Today, i will show you other details to complete the discussion.   It will be a short post but the next time then we will talk about residual predicates and it will be a very interesting topics! Finally, thanks to a suggestion of ​​my friend Alessandro Alpi there will also an other post in which we will talk about composite indexes and how, in this case, the index search takes place. Enjoy the reading!   Other infos about Singleton lookup and Range Scan In the previous post, we talked about Singleton lookup and Range Scan . Now we know how record are phisically searched inside an index.   We have seen that it is not easy to know which method we are using. In this case DMVs comes to our aid!   Dynamic Management Views (DMVs) and Dynamic Management Functions (DMFs) a...

Hi Guys, Welcome back for another important post here on my blog! Today we are going to deepen the functioning of a seek and see in more detail how it works . I hope many of you are reading this post. My goal is in fact to explain in the clearest and most interesting way how SQL Server works. If something is not clear to you, just ask, it will help me to improve. Last news before start, in case you are genuinely and truly interested in one of the products that appear in advertising ... click the adv from my blog to support my site! Crew, let's go !!!    Recap about index and the way them works Well, first of all we must do a recap about indexes and about the way them works .   I blogged many times about index for example, i suggest to read here: SQL Server, Difference between a seek and a scan operation and the Latch coupling An index, clustered or not, has the following structure: Every search start from the Root Page, then continue to the Intermediate pages and finall...