SQL Server B-Tree
When you think of B-trees, think “clustered index”. All indexes in SQL Server on disk-based tables are structured […]
SQL Server
SQL Server Pages and Extents
The page is the fundamental unit of data storage in SQL Server. An extent is a collection of […]
SQL Server Internal Data Structures
As opposed to the logical query processing discussed in the post SQL Server Logical Query, we are now […]
SQL Server Top N per Group
The top n per group is a classic task in SQL. One example of this task is “give […]
SQL Server Top N per group row_number Single Table
This post provides a solution to the classic top n per group task where you have a single […]
SQL Server Cross Apply General Form
“The APPLY operator is one of the most powerful tools I know of in T-SQL, and yet it […]
SQL Server Inline Table-Valued Functions (TVF)
Suppose you need a reusable table expression like a view, but you also need to be able to […]
SQL Server Multi-Join Queries
Multi-Join Queries So far we have just joined two tables together. Now we will work with four tables, […]
SQL Server Subqueries
Subqueries allow you to nest queries. One query operates on the results of another query. Another way to […]
SQL Server Aggregate Window Functions Raptors
This post is another example of aggregate window functions. This time we are going to use some Toronto […]
SQL Server Derived Tables
A derived table closely resembles a subquery. It is a table subquery that is defined in the FROM […]
SQL Server Self-Join
A self-join is a join between multiple instances of the same table. With self-joins it is mandatory to […]