SQL Server Performance Blog where milliseconds matter

Hi Guys, Welcome to this a bit off topic post. I must admit I am a huge fan of wikipedia. Wikipedia is free multilingual online encyclopedia born with the intent to collect all human knowledge. But not only is it free and multilingual, it is also collaborative.  Anyone can contribute according to certain criteria. If Wikipedia aims to collect all the human knowledge, there is also a parallel wiki that instead aims to catalog all this knowledge. We are talking about wikidata . Like Wikipedia, Wikidata is also a free and open knowledge base that can be read and edited by humans and machines.    In addition, Wikidata serves as a central repository for the structured data of Wikimedia projects, including Wikipedia but also Wikivoyage, Wiktionary, Wikisource and others.  Returning to practical, for example, every page of wikipedia is linked to an element of wikidata. Wikidata is therefore responsible for cataloging all this information through a series of properties and ...

Hi Guys, After an almost exact month from the first release candidate (RC0) a new release candidate has been released. We talked about the innovations introduced by the RC0 here: SQL Server 2022 RC0, new features and capabilities. The great improvement of the TRIM function, Integrated acceleration and other features   Now it is time to take a look to this RC 1!       SQL Server 2022 Release Candidate 1 This new release candidate (RC) was announced on September 22, 2022 and has a version number 16.0.950.9 Microsoft also said that the Linux version will be out soon. This release candidate introduces a feature called Hybrid buffer pool with direct write as well as other improvements. But, what is the hybrid buffer pool feature? Hybrid Buffer Pool The Hybrid Buffer Pool feature was introduced in SQL Server 2019 (15.x) and now is further enhanced in SQL Server 2022 (16.x). This technology enables buffer pool objects to reference data pages in database files residing on...

Hi guys, Welcome to an atypical post! In this post I want to tell you a little bit about the history of the vast world of databases .  I will take this opportunity to talk about database theory . I know! ... it’s been a while! Today we talk about Dr. C. Mohan . But who is Dr. Mohan? Chandrasekaran Mohan is an Indian-born American computer scientist.   Does this name mean anything to you?  What if I told you that it was the person who conceived the ARIES family of algorithms?   But let’s start from the beginning..   Enjoy!   C.Mohan and the ARIES Algorithm Chandrasekaran Mohan is an Indian-born American computer born in Tamil Nadu (India) in 1955. After growing up there and finishing his undergraduate studies in Chennai, he moved to the United States in 1977 for graduate studies. He received his PhD in computer science from the University of Texas at Austin in 1981. After finishing his PhD in the database area in December 1981, Mohan joined IBM Research, the...

Hi Guys, I don’t usually talk about numbers but I have to say that almost 8000 clicks in just one month on my blog is really a huge amount! So, thanks to the 7000 k friends who follow me! In the last post (click here) we saw in detail how the tempDB database works. Today we see how to use what we learned to write in temporary tables as quickly as possible. In this way you can put your hand to your procedures to make them run ...and for free! Let’s see how to exploit the temporary table cache mechanism!  Enjoy! Temporary Table Caching In the previous post we saw that there are some rules to take advantage of the temporary table caching . We said that in the following cases table are not cached : Named constraints are not created DDL statements that affect the table are not run after the temporary table has been created.  for example the CREATE INDEX or CREATE STATISTICS statements Temp table is not created by using dynamic SQL Temp table is created inside another object,...

Hi Guys, Welcome back to this blog. Today we will talk about slowness . Qne of the most frequently asked questions is almost certainly: why is my SQL Server so slow? Today we will answer this question. But not only that. We will make a nice talk about the tempdb database to finally get to see what improvements SQL Server 2022 brings us on this front. Fasten your seat belts and enjoy the reading     W hy is my SQL Server so slow?     Let’s start by saying what is the TempDB database .   The TempDB database is a temporary system database even if its structure is essentially just like any other user database.  It is temporary in the sense that it is emptied every time the SQL Server instance is restarted . What exactly is written in the TempDB database? Well, first of all goes into the TempDD temp tables and table variables The creation of a temporary (#) table on a user database "IS A" creation of a table in the TempDB: Similarly ...the same thing happens wh...