Define Partial-artificial-alternate-compound

Question

Give a brief explanation of the term partial, artificial, alternate, compound and natural key.

Answer 1

It is a set and collection of attributes which can uniquely identify weak entities and which are related to equivalent owner entity. It is sometime named as Discriminator.

Alternate Key: All the Candidate Keys without the Primary Key are recognized as Alternate Keys.

Artificial Key: When no obvious key either stands alone or compound is accessible, then the last resort is to easily make a key, through assigning a unique number to each and every record or occurrence. Then this is recognized as developing an artificial key.

Compound Key: When no single data element uniquely determines occurrences in construct, then combining multiple elements to make a unique identifier for construct is recognized as creating a compound key.

Natural Key: If one of data elements kept in a construct is employed as the primary key then it is named as natural key.