1. What is Relationship?

It is an association among two or more entities.

2. When is a functional dependency F said to be minimal?

•  Every dependency in F has a single attribute for its right hand side.
•  We cannot replace any dependency X A in F with a dependency Y A where Y is a proper subset of X and still have a set of dependency that is equivalent to F.
•  We cannot remove any dependency from F and still have set of dependency that is equivalent to F.

3. What is a Relation Schema and a Relation?

A relation Schema denoted by R(A1, A2, …, An) is made up of the relation name R and the list of attributes Ai that it contains. A relation is defined as a set of tuples. Let r be the relation which contains set tuples (t1, t2, t3, ..., tn). Each tuple is an ordered list of n-values t=(v1,v2, ..., vn).

4. What is an Extension of entity type?

The collections of entities of a particular entity type are grouped together into an entity set.

5. What is 3NF?

A relation schema R is in 3NF if it is in 2NF and for every FD X A either of the following is true

•  X is a Super-key of R.
•  A is a prime attribute of R.

In other words, if every non prime attribute is non-transitively dependent on primary key.

6. What is Relationship type?

Relationship type defines a set of associations or a relationship set among a given set of entity types.

7. What is Weak Entity set?

An entity set may not have sufficient attributes to form a primary key, and its primary key compromises of its partial key and primary key of its parent entity, then it is said to be Weak Entity set.

8. What is Relational Algebra?

It is procedural query language. It consists of a set of operations that take one or two relations as input and produce a new relation.

9. What is degree of Relationship type?

It is the number of entity type participating.

10. What is database Trigger?

A database trigger is a PL/SQL block that can defined to automatically execute for insert, update, and delete statements against a table. The trigger can e defined to execute once for the entire statement or once for every row that is inserted, updated, or deleted. For any one table, there are twelve events for which you can define database triggers. A database trigger can call database procedures that are also written in PL/SQL.