Database Questions

A view may be a subset of the database or it may contain virtual data that is derived from the database files but is not explicitly stored .

High level data models provide the concepts that are close to the way many users perceive data

The relationship where both the participating entities belong to same entity type is called Recursive relationship

The time complexity of sequential search is O(n)

The description of a data base is called the database schema , which is specified during database design and is not expected to change frequently . A displayed schema is called schema diagram .We call each object in the schema as schema construct.

Database provides necessary means to achieve this abstraction. By structure of a database we mean the data types, relations, and constraints that should hold on the data.

Can’t delete a row from primary table if there are related rows in secondary table.