In this blog article I will briefly describe the purpose of tables in a database which is part of our 98-364 Database Fundamentals Exam Guide
The main purpose of tables is to store data in an organized way that allows to achieve company objectives. One database almost always contains multiple tables that represent enity (for instance Customer, Product, Order) and they relate to each other, for instance Customer buys a product and receive unique Order Number.
In our definition we mentioned to achieve company objectives. This is quite important because it affects how tables are designed and there are different techniques depending on objective.
Purpose of table is not limited to simply store data and it helps to achieve other objective like:
- Enforces uniqueness (for example one customer generally (exception is data warehouse) should be recorded only once in a customer table)
- Allow users to enter only valid values (using data types and constraints)
- Make the data sharable with others (database is generally on a server and can be used by multiple departments)
- Enforce referential integrity and that means that you cannot have order without a customer.
- Quick access to data. Tables or more precisely indexes (that are create for tables) allow quick access to data.