db-900 relational data

Question 1

What is data normalization?

Answer 1

A schema design process that minimizes duplication of data and enforces data integrity

Question 2

What are the 4 common steps of normalization?

Answer 2

1. each type of “entity” gets its own table
2. each type of “attribute” gets its own column
3. Each unique instance of an entity gets a unique identifier (ID column)
4. Use “foreign keys” to link entities across tables

Question 3

What are the common SQL dialects?

Answer 3

T-SQL
MySQL
pgSQL
PL/SQL

Question 4

What is T-SQL?

Answer 4

This is the language used by SQL Server, it stands for Transact-SQL

Question 5

What is pgSQL

Answer 5

Language used by postgres

Question 6

What is PL/SQL

Answer 6

This is used by Oracle, stands for Procedural Language SQL

Question 7

What are the three categories of SQL statements?

Answer 7

Data Definition Language (DDL)
Data Control Language (DCL)
Data Manipulation Language (DML)

Question 8

What are the common DDL operations?

Answer 8

Create, Modify, Delete objects in the database (tables, procedures, views, etc)

Question 9

The most common DDL statements are:

Answer 9

1. Create
2. Alter
3. Drop
4. Rename