Difference Between DBMS and RDBMS

Parameter	DBMS	RDBMS
Acronym for	Data Base Management System	Relational Data Base Management System
Relation	Data is stored in flat file oriented System and no relations are used.	It provides facility to create relation between tables.
Dr. E.F. Codd Rules	Only 3 rules, Out of 12, are followed by DBMS. (from Rule 0 to Rule 12)	Minimum 6 rules, Out of 12, are followed by RDBS. (from Rule 0 to Rule 12)
Data Security	It can’t implement constraints in Tables and has less Security. The ACID (Atomicity, Consistency, Isolation and Durability) property of the database is ensured by Programmer.	It can implement the integrity constraint for the purpose of holding ACID (Atomicity, Consistency, Isolation and Durability) property of the database and is much securing than DBMS.
Generation	3GL	4GL

Difference Between Database and Data Warehouse

Parameter	Database	Data Warehouse
Definition	Organized Collection of Data is called database.	Database of Databases is Called Data Warehouse.
Purpose	It is designed to allow the definition, creation, querying, update, administration of data (Transaction Processing).	It is a relational database that is designed for query and analysis rather than transaction processing.
Data Type	Data stored in Database is up to date.	Current and Historical Data is Stored in Data Warehouse.
Orientation	Transaction Oriented: e.g. Each Transaction of Bank Customer is written to database and is interpreted as Accounting Database.	Subject Oriented: The data in the data warehouse is organized so that all the data elements relating to the same real-world event or object are linked together.

Difference Between Data Mining and Machine Learning

Parameter	Data Mining	Machine Learning
Definition	Data mining is a process to extract information from a data set and transform it into an understandable structure for further use.	It is a Technique that concerns the construction and study of systems that can learn from data.
Focus	It focuses on the discovery of unknown properties in the data.	It focuses on prediction, based on known properties learned from training data.
Database Size	It is an automatic or semi-automatic analysis that is performed on large quantities of data.	It is generally performed on small databases to increase accuracy.
Types	Association Rules Classification Clustering Sequential Patterns Sequence Similarity	Supervised Un Supervised Reinforcement

Distributed Data Processing (DDP)

It is a configuration in which many geographically dispensed or distributed independent computers are connected by means of computer networks. In this type of configuration Programs, data and other resources are shared among several users who are geographically far away from one another. This provides the facility of better resource use to the end users.

This approach is different from centralized system because computers are installed at different locations and each of them performs independent data processing. Each computer in DDS is designed for a specific task.

Database Management System (DBMS) Interfaces

DBA Interface: This interface is used by the database administrator to create databases, Users, to set system parameters for changing database schema etc. Fig. given below shows admin menu where DBA is can create new user and can assign privileges to him.

Classification of Database Management System

Database Management System can be classified on several DBMS criteria.

A) On the Basis of Data Models.

Data model is a collection of high level data description that hides many low level storage details. A data Model has following three Components:
1) A Structural Part that consist of a set of rules according to which database is constructed.
2) A Manipulating Part That defines type of operations that are allowed on data.
3) A set of integrity rules that ensures that data is correct.
The Data Models are further divided into Three Categories: 

DBMS Languages

 DBMS Support a variety of users and provides appropriate languages and interface or each category of users.Here are some languages that are provided by DBMS:
1) Data Definition Language (DDL): This Language is used define data structures and specially database schemas. these statements are used to create, alter, or drop data structures. ALTER ,CREATE ,DROP are some examples of DDL.

2) Storage Definition Language (SDL): This language is used to define internal schema. It defines that what will be the Physical structure of database, How many bites per field will be used, what will be the order of fields, and how records will be accesses etc.

Database Independence

"The ability to change the Schema at one level of database system without having to change the Schema at the next higher level is called data independence". Data Independence is divided into two categories:

1) Logical Data Independence: It is the ability to change conceptual schema without making any changes to application programs or external schema. In Logical data Independence new rows and columns are added without changing user views and programs.it is more difficult to achieve rather than Physical Data Independence.

2) Physical Independence: It is the ability to change internal schema without making any changes to conceptual schema.Hence there is no need to change the external schema.Physical data independence hides all details of storage structure from user applications. Modifications at physical level improves performance and any new change is absorbed by the mapping techniques.

DBMS Users

It is very difficult to design and maintain large databases for a single user.To perform such activities no. of users are involved .These users are called DBMS users and can be categorized as:-
1) Database Administrator: DBA is a person that performs installation, configuration, up gradation monitoring and maintenance of databases in an organization.He is also responsible for the database recovery and security.

2) Database Designers: Database designers are responsible for data identification that is to be stored and choosing database structure that represents and stores this data.They communicate with the user and designs database as per their requirements. They creates Tables, Indexes, Views, Constraints, Triggers, Storage Parameters etc. 

Difference Between Relational Algebra and Relational Calculus

Sr. No.	Relational Algebra	Relational Calculus
1	It is Procedural query language.	It is non-procedural query language.
2	It deals with what to do and how to do.	It only deals with how to do.
3	It consists of a set of operations that take one or two relations as input and produces a new relation as the output.	In relational calculus, we must write a sequence of operations to specify a retrieval relation.

Advantages of DBMS

Sr. No.	Advantage	Description
1	Reduced Data Redundancy	With the use of DBMS data redundancy is reduced. Since all data is stored at one centralized place and chances of data duplicity are very rare.
2	Data Inconsistency	Data inconsistency exists when different and conflicting versions of the same data appear in different places. Since in DBMS data is stored at centralized place and data duplicity is avoided which also reduces the Data Inconsistency.
3	Centralized Access	Since data is stored at central place and can be used by any connected client as per rights given to him.
4	Data Integrity	With the help of Centralized control adequate checks are incorporated in the DBMS to provide data integrity. This assures that the data contained in the database is both correct and consistent. Data values being entered for the storage could be checked to ensure that they fall within a specified limit and follow the correct format.
5	Data Security	Since it user has limited rights as per his/her requirements. Only those part is made visible to user which is desired by the user and rest of data is hidden.
6	Concurrent access	Same data can be used by different users at the same type.
7	Efficient data access	DBMS uses no. of sophisticated techniques to store and retrieve data efficiently. This feature is very important if the data is stored on external storage devices.
8	Data Independence	The DBMS can provide an abstract view of the data to insulate application code from details of data representation and storage.
9	Data Administration	Centralized data can be used for improvements or to identify loop falls.

Database Normalization

Database Normalization is the process of organizing data in a database by eliminating redundancy and inconsistent dependency. it divides large tables into smaller tables ,which are less redundant , and defines relationships between them.The Main motive is to isolate data so that additions, deletions, and modifications of a field is made in just one table and then propagated through the rest of the database using the defined relationships.

Database normalization uses few rules . Each rule is called a “normal form.” If the first rule is observed, the database is said to be in “first normal form.” If the first three rules are observed, the database is considered to be in “third normal form.” Although other levels of normalization are possible, third normal form is considered the highest level necessary for most applications.

Normalization Form	Description	Example
First normal form (1NF)	It is a property of a relation in a relational database. A relation is in first normal form if the domain of each attribute contains only atomic values, and the value of each attribute contains only a single value from that domain	For example, to track an inventory item that may come from two possible sources, an inventory record may contain fields for Vendor Code 1 and Vendor Code 2.
Rules	i) Eliminate repeating groups in individual tables. ii) Create a separate table for each set of related data. iii) Identify each set of related datawith a primary key.
Second Normal Form(2NF)	A table is in 2NF if and only if it is in 1NF and no non-prime attribute is dependent on any proper subset of any  candidate key of the table. A non-prime attribute of a table is an attribute that is not a part of any candidate key of the table.	For example, consider a customer’s address in an accounting system. The address is needed by the Customers table, but also by the Orders, Shipping, Invoices, Accounts Receivable, and Collections tables. Instead of storing the customer’s address as a separate entry in each of these tables, store it in one place, either in the Customers table or in a separate Addresses table.
Rules	i) Create separate tables for sets of values that apply to multiple records. ii) Relate these tables with a foreign key.
Third Normal Form(3NF)	a table is in 3NF if and only if both of the following conditions hold: i)The relation R (table) is in second normal form (2NF) ii)Every non-prime attribute of R is non-transitively dependent (i.e. directly dependent) on every superkey of R.	For example, in an Employee Recruitment table, a candidate’s university name and address may be included. But you need a complete list of universities for group mailings. If university information is stored in the Candidates table, there is no way to list universities with no current candidates. Create a separate Universities table and link it to the Candidates table with a university code key.
Rules	Eliminate fields that do not depend on the key