File base system with data base system and RDBMS

File based system: 

File-based System is a collection of application programs that perform services for the end-users such as the production of reports. Each program defines and manages its own data. By having files stored on computers, the data could be accessed more efficiently.

Limitation

1. Data Redundancy:

It is possible that the same information may be duplicated in different files.this leads to data redundancy results in memory wastage.

2. Data Inconsistency:

Because of data redundancy , it is possible that data may not be in consistent state.

3. Difficulty in Accessing Data:

Accessing data is not convenient and efficient in file processing system.

4. Limited Data Sharing:

Data are scattered in various files.also different files may have different formats and these files may be stored in different folders may be of different departments.

So, due to this data isolation, it is difficult to share data among different applications.

5. Security Problems:

Database should be accessible to users in limited way.

Each user should be allowed to access data concerning his requirements only.

Overcoming the Limitations of File Processing

Data independence:

 With the traditional applications-based file approach, the programs would have to be revised to provide access to more or less data.

Privacy:

The security modules available through DBMS software can contain powerful features to protect the database against unauthorized disclosure, alteration, or destruction. Control over data access can typically be exercised down to the data element level. Users can be granted access to data for reading or updating (add, revise, delete) data. Other ways to implement security include data classification(i.e., data objects are given classification levels and users are assigned clearance levels) and data encryption

Database and DBMS

Database:

 An organized collection of related information so that it can easily be accessed ,manage and update.

DBMS:

1) Stands for database management system.

2) A software system for creating ,organizing and managing the database.

3) It provides an environment to the user to perform operations on the database for creation, insertion, deletion, updating and retrieval of  data.

Advantages of DBMS

1) Controlling data redundancy

2) Data consistency

3) Control over concurrency

4) Backup and recovery procedure

5) simplicity

6) Data sharing

7) Integrity constraints 

8) Data security 

9) Data independence

Relational database management System(RDMS)

RDBMS is  based on relational model  defined by E.F.codd . In rdbms   data is stored in the forms of row and column.

RDBMS use the language known as SQL .SQL is simple programming language used for accessing and managing data in the form of relational database

ELEMENTS of rdbms

There are for elements of RDBMS

 1-Table 

 2-Tuple      

 3-Attributes     

 4-Queries

FEATURES of RDBMS

1) Provides   data to be stored in the form of tables.

2) Persists data in the form of rows and column 

3) Provides the primary key  to uniquely identify the rows in table.

Rules of RDMS

Each table has ha unique name

Each table  has multiple rows

Each row in table is unique

Every table has key to uniquely  identify the rows.

Each column in table  has a unique attribute name.

Example:

Advantages of RDBMS

It is easy to use.

➨It is secured in nature.

➨The data manipulation can be done.

➨It limits redundancy and replication of the data.

➨It offers better data integrity.

➨It provides better physical data independence.

➨It offers logical database independence i.e. data can be viewed in different ways by the different users.

➨It provides better backup and recovery procedures.

➨It provides multiple interfaces.

➨Multiple users can access the database which is not possible in DBMS.