Chapter 15: Implementing Indexes and Statistics

Question 1

How long is a page?

Answer 1

A 8 KB and belongs to a single object.

Question 2

How are pages organized?

Answer 2

Into extents. An extents consists of eight consecutives pages.

Question 3

What is the main difference between an uniform extent and a mixed extent?

Answer 3

An uniform extent just belong to an only object, whereas a mixed extent belong to more than an object.

Question 4

How is the data organized in SQL Server?

Answer 4

In pages.

Question 5

How SQL Server organizes the tables?

Answer 5

As heap or as balanced tree.

Question 6

What is a clustered table/clustered index?

Answer 6

A table organized as balanced tree.

Question 7

What happens when a table is created without specifying a primary key or unique constraint?

Answer 7

The table is organized as a heap.

Question 8

What is IAM?

Answer 8

SQL Server traces which pages and extents belong to an object through special system pages called Index Allocation Map (IAM) pages.

Question 9

What kind of information stores the view sys.indexes?

Answer 9

General information about tables and their indexes.

Question 10

What kind of values stores the column “type” for the view sys.indexes?

Answer 10

0 for Heaps, 1 for clustered tables (indexes) and 2 for nonclustered tables (non indexes).