Tables and Indexes: Internal Structure and Access Methods
SQL Server stores data in tables and indexes. They represent a collection of data pages with rows that belong to a single entity.
By default, the data in the tables is unsorted. You can store it in sorted order by defining the clustered index on the table. Moreover, you can create nonclustered indexes that persist another copy of the data from the index columns sorted in a different order.
In this chapter, we will talk about the internal structure of the indexes, cover how SQL Server uses them, and discuss how to write queries in a way that efficiently utilizes them.
Heap Tables ...