Lecture notes Mca (BMCA1)

INDEX

UNIT NO TOPIC PAGE NO

File Processing System Vs DBMS. 01 - 08

Characteristics of DBS. 04-05

I Architecture of a database. 06 – 08

DBMS Languages. 10-13

Database users and DBA. 14-17

Entity set and Relationship set. 19-23

Design Issues of ER model-Constraints 24-28

primary key, Super key, candidate 29-31
keys. Introduction to relational model-
II Tabular.
Representation of Various ER Schemas. ER 32-33
Diagram Notations.
Goals of ER Diagram- Weak Entity Set. 32-33

Views, Triggers. 33-39

The Form of Basic SQL Query - 42-43
UNION, INTERSECT, and EXCEPT–-
Aggregate
join operations: equi join and non equi join. 43-44
III
Nested queries - correlated and uncorrelated. 45-46

Functions-Null values, GROUPBY-
HAVING Clause. 47-49


Normalization – Introduction,
unctional dependencies, First, Second, 50-59
IV and third normal forms .


Boyce/Codd normal form. 60-63
Higher Normal Forms - Introduction,

, dependency preservation, Multi-valued 63-67
dependencies and Fourth normal form.


69-70
Transaction concept, transaction state.
Properties of a Transaction, concurrent
71-72
executions.

V Serializability, recoverability. 73-75

Implementation of isolation, 76-78

Testing for serializability. 78-80

, UNIT 1
Database: File Processing System Vs DBMS, History, Characteristic-Abstraction levels,
Architecture of a database, Functional components of a DBMS, DBMS Languages-Database
users and DBA.

File Processing System Vs DBMS

1. A database management system coordinates both the physical and the logical access
to the data, whereas a file-processing system coordinates only the physical access.

2. A database management system is designed to allow flexible access to data (i.e.
queries), whereas a file-processing system is designed to allow predetermined access
to data (i.e. compiled programs).

3. A database management system is designed to coordinate multiple users accessing the
same data at the same time. A file-processing system is usually designed to allow one
or more programs to access different data files at the same time. In a file-processing
system, a file can be accessed by two programs concurrently only if both programs
have read-only access to the file.

4. Redundancy is control in DBMS, but not in file system.

5. Unauthorized access is restricted in DBMS but not in the file system.

6. DBMS provide backup and recovery whereas data lost in file system can't be
recovered.

7. DBMS provide multiple user interfaces. Data is isolated in file system.




1

, DBMS File Processing System
Minimal data redundancy problem in
Data Redundancy problem exits
DBMS
Data Inconsistency does not exist Data Inconsistency exist here
Accessing database is easier Accessing is comparatively difficult
Data is scattered in various files and files
The problem of data isolation is not
may be of different format, so data isolation
found in database
problem exists
Transactions like insert, delete, view,
In file system, transactions are not possible
updating, etc are possible in database
Concurrent access and recovery is Concurrent access and recovery is not
possible in database possible
Security of data Security of data is not good
A database manager (administrator)
A file manager is used to store all
stores the relationship in form of
relationships in directories in file systems.
structural tables



History of Database

1950s and early 1960s:
o Data processing using magnetic tapes for storage
o Tapes provided only sequential access
o Punched cards for input

Late 1960s and 1970s:
o Hard disks allowed direct access to data
o Hierarchical and network data models in widespread use
 IBM’s DL/I (Data Language One)
 CODAYSL’s DBTG (Data Base Task Group) model
 → the basis of current DBMSs
o Ted Codd defines the relational data model
 IBM Research develops System R prototype
 UC Berkeley develops Ingres prototype
o Entity-Relationship Model for database design
1980s:

o Research relational prototypes evolve into commercial systems


2