Let’s understand a few reasons why SQL Server (sometimes) does not show missing index hints. We are using AdventureWorks2016 database for the demo. Let’s make a copy of Sales.Customer table as Sales.CustomerDup SELECT * INTO sales.customerdup FROM sales.customer Before jumping into the actual query, have a look at AccountNumber column which is of VARCHAR data [...]
SQL Server Management Studio 18.6 and Azure Data Studio July 2020 release, 1.20. Your favourite SSMS has been updated again. Version 18.6 is released. The long pending Database Diagram issue has been fixed along with couple of other fixes. There are new features too. Checkout the release notes. For many good reasons, people are getting [...]
In this blog post, we will observe Double Read Phenomenon in SQL Server. You will see how the same record is read twice in a single SELECT query/operation. First watch this video. Now, explanation. So why does this happen? Let’s go step by step. Step 1 First, user 1 fires an UPDATE in an explicit [...]
In this blog post, we will see how deadlocks can happen in SQL Server due to Bookmark Lookups. Let’s create a dummy table WideWorldImporters & associated indexes. This will be our test data to play with. use WideWorldImporters GO -- create a opy of sales.customers select * into sales.customers2 from sales.Customers -- create clustered index [...]
Faster INSERTs in Tempdb – Optimized/Minimal Tempdb Logging In this blog post, we will see how SQL Server optimises Tempdb logging for faster CRUD operations. For the purpose of this tutorial, we will perform the same operations in a regular user database versus Tempdb, and note down execution time (performance comparison). Thanks to Hugo Kornelis, [...]
The phrase Sargability is quite popular in SQL Server world. Wikipedia says: “In relational databases, a condition (or predicate) in a query is said to be sargable if the DBMS engine can take advantage of an index to speed up the execution of the query. The term is derived from a contraction of Search ARGument [...]
In this video, you will see that SQL Server can, sometimes, recommend more than one index hint for a given query, but it is not so evident. Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation [...]
In this video, you will understand what really Clustered Index Seek means and why it can be misleading, sometimes. Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). Hope the video was worth [...]
In this video, you will understand how to use PAGEIOLATCH Wait Type metrics to detect/identify IO slowdown Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). Hope the video was worth your time. [...]
In this video, you will understand how Avg. Disk sec/Read performance monitor counter can be used to identify/detect/compute read latency on slow IO. Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). Hope [...]
In this video, you will understand how sys.dm_io_virtual_file_stats can be used to identify/detect/compute read latency on slow IO. Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). Hope the video was worth your [...]
In this video, you will understand how is the histogram computation (SQL Server Statistics Data) used by the Query Optimizer for cardinality estimation. Particularly, you will see the usage of EQ_ROWS & AVG_RANGE_ROWS. Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos [...]
In this video, you will learn why you should not blindly follow the SSMS Missing Index Hints. Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). Hope the video was worth your time. [...]
In this video, you will learn some quick techniques to identify which stats objects are being used by the SQL Optimizer. These techniques can help you in your query tuning endeavors. Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to [...]
In this video, you will understand the basics of SQL Server Statistics. How are they created and how are they updated. Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). Hope the video [...]
In this video, you will understand the basics of SQL Server Statistics. How are they created and how are they updated. Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). Hope the video [...]
In this video, you will understand the following concepts: SQL Server Query Cost, Memory Grant & SQLRESERVATIONS Memory Clerk Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). Hope the video was worth [...]
In this video, I am demonstrating how to track waits stats for a given query/session using Extended Events. You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). All DPG members (membership is free) have free access to many learning resources including in-person events, [...]
In this video, I am demonstrating the difference between session level waits and task level waits. You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). Get new content directly in your inbox - Click here Hope the video was worth your time. Happy [...]
In this video, I am demonstrating a few common wait types in SQL Server. Get new content directly in your inbox - Click here You can also visit DataPlatformGeeks (DPG) Video Library to watch more videos and to download video resources (presentation & demo code). Hope the video was worth your time. Happy Learning. [...]
