Chapter 8

Question 1

What is horizontal splitting

Answer 1

In horizontal splitting, rows are split and columns numbers remains same in new tables

Question 2

What are benefits of horizontal splitting

Answer 2

• Security
• Graceful degradation of databases in case of table damage
• Performance

Question 3

What are b-trees

Answer 3

Binary trees are data structures for large data sets

Question 4

What are extra baggage in vertical splitting

Answer 4

Such columns which have excessive information stored which makes the query result slow. And also such columns which are rarely accessed.

Question 5

What is pre-joining

Answer 5

Identify frequent joins and append tables together in the physical model. It is generally used for 1:M relationship.

Question 6

What is market basket analysis

Answer 6

It is a typical scenario for pre-joining. Sometimes, a product sell also have another product sell along with it. Join is always use in such scenario.

Question 7

Which table is greater, master or detail

Answer 7

Detail table is 3-4 times larger than master

Question 8

What is adding redundant columns

Answer 8

Sometime it happens that we need one column from table 2 and we need to make a join along table 1 and table 2. We can do, is to add that one column to table 1 so we could avoid join query.