Basic Terms Flashcards
(24 cards)
What is primary goal of a DBMS?
Provide a way to store data and retrieve database information that is both convenient and efficient.
Define data inconsistency.
When various copies of same data do not agree.
What are some major problems with a file processing system?
Data Redundancy and Inconsistency Difficulty in accessing data Data isolation Integrity Problems Atomicity problems Concurrent access anomalies Security problems
What are three levels of data abstraction?
Physical, Logical, View
Define Schema.
Overall design of a DB is called Schema.
Name two types of DML.
Procedural, Non Procedural
What is a query?
A statement requesting the retrieval of information.
What is a relationship?
An association among several entries.
Give names of components involved in query processor.
Application Program Object Code Compiler and Linked DML queries DML Compiler and organiser DDL interpreter Query evaluation engine
Give names of components at storage manager level.
Buffer Manager
File Manager
Authorisation and Integrity Manager
Transaction Manager
Give name of elements at storage level.
Data
Indices
Data Dictionary
Statistical Data
Name different type of DBMS users
Naive
Application Programmers
Sophisticated Users
Specialised Users
What is the difference between two tier and three tier architecture of Databases?
Application is divided into application client and application server in three tier architecture.
What is an entity?
An object that exists and can be differentiate from other objects.
Define Entity Set.
It is a set of entities of same type having same properties.
What is a relationship?
An association among several entities.
What is degree of a relationship set?
Number of entity sets that participate in a relationship set.
What is a domain?
Set of permitted values for an attribute.
Mention names of cardinality constraints for binary relationship set.
One to one.
One to many.
Many to one.
Many to many.
Define Super Key.
A set of one or more attributes whose values uniquely determine each entity.
Define candidate key.
Minimal subset of candidate key that uniquely determines each entity.
Tuple is a row or column?
Row
Attribute is a ________ in a table.
Column
Relational algebra is __________ and Relational calculus is __________
Procedural, Non Procedural
