1. What is DML Compiler?

It translates DML statements in a query language into low-level instruction that the query evaluation engine can understand.

2. What is Data Independence?

Data independence means that “the application is independent of the storage structure and access strategy of data”. In other words, The ability to modify the schema definition in one level should not affect the schema definition in the next higher level.

Two types of Data Independence:

•  Physical Data Independence: Modification in physical level should not affect the logical level.
•  Logical Data Independence: Modification in logical level should affect the view level.

NOTE : Logical Data Independence is more difficult to achieve

3. What is an Entity type?

It is a collection (set) of entities that have same attributes.

4. What are the different phases of transaction?

Different phases are

•  Analysis phase
•  Redo Phase
•  Undo phase

5. What is normalization?

It is a process of analysing the given relation schemas based on their Functional Dependencies (FDs) and primary key to achieve the properties

•  Minimizing redundancy
•  Minimizing insertion, deletion and update anomalies.

6. What is extension and intension?

Extension -   It is the number of tuples present in a table at any instance. This is time dependent.

Intension -   It is a constant value that gives the name, structure of table and the constraints laid on it.  

7. What is VDL (View Definition Language)?

It specifies user views and their mappings to the conceptual schema.

8. What is Record-at-a-time?

The Low level or Procedural DML can specify and retrieve each record from a set of records. This retrieve of a record is said to be Record-at-a-time.

9. What is Domain-Key Normal Form?

A relation is said to be in DKNF if all constraints and dependencies that should hold on the the constraint can be enforced by simply enforcing the domain constraint and key constraint on the relation.

10. What are the primitive operations common to all record management systems?

Addition, deletion and modification.