Question

1. You are designing a new database to track corporate customers and their monthly billing. The database consists of customer data and lookup tables. Explain how you would choose the primary keys for the entities you are creating.  
2. What are some of the potential risks that arise when using surrogate keys in place of natural keys?

Answer 1

In the given question, for creating a database of the customers and their monthly billing, the primary key to be choosen should be a  uniquely identified key which represents a particluar record. In other words, it should be unique to every record and cannot be same for two records. Therefore, it should be chosen in such a way such that, it isuniques to every corporate customer. For Eg: It can be some Id allotted to them

In the second part, risk of surrogate keyin place of natural key is to be provided, before which we need to know the meaning of both.

Natural Key: It is that value which naturally exists in the record and has relation with the table whereas Surrogate Key is a made up value only for the purpose of uniquely identifying a column and does not naturallu exist but is made up.

Now the risk of using surrogate keys instead of natural keys:

• It can be misleading as it carries no relevance in the data
• Transfering data might be become difficult as the new database should not have same surrogate keys
• Excess usage of space because of extra space
• Sometimes, creating surrogate key becomes difficult