SQL Server
Microsoft SQL Server is a
relational database management system developed by Microsoft. Function
of this product is to store retrieve data as
required by other applications.
This post explains some basics about data,
information, database and its characteristics, ACID properties and advantages
of DBMS.
Introduction
Data: Raw fact and figures
Example:
Name, roll number, invoice number
Information: Processed or more useful form of
data. It helps in decision making process
Example: Time
table, merit list, progress card
Knowledge: Information containing wisdom,
derived from fundamental processing and organizing
Database
The related information
when placed in an organized form makes a database
Ex:
Dictionary, telephone directory etc.
Unorganized information
has no meaning
Common operations on a database
- Selection
- Insertion
- Updating
- Deletion
Building Blocks of a Database
- Columns
- Rows
- Tables
Characteristics of a database
- Organized/Related
- Shared
- Permanent or persistence
- Validity, Integrity, Correctness
- Security
- Consistency
- Non Redundancy
- Independence
- Easily Accessible
- Recoverable
- Flexible to change
ACID Properties
Atomicity: All
transactions are done or none of them
Consistency:
Database remains same before and even after the transaction
Isolation:
Cannot access the data in intermediate state
Durability:
Transaction will persist after success message.
Database Management
System
- Set of programs that organizes
and maintains the information.
- Primary objective is to provide
convenient environment to retrieve and store the database information.
- It supports single user and
multiuser environment.
- Ensures the data accuracy – Data
Integrity
- DBMS in market: Dbase, Oracle, SQL Server etc.
Components of DBMS Environment
- Hardware
- Software
- Data
- Users
Hardware
- Computer system
- Storage devices
- I/O devices
Software
- Software is actual DBMS
- Interface between physical data
and users
- Requests handled by DBMS
- Provide simple Interface
- Mediator b/w database and user
- Utilities
- Examples: MS Access, Oracle
Data
- Most important component of DBMS
- Bridge between machine and user
Users: Different users can access the
data Depending on their degree of expertise. Users are classified in the
following groups
- Native users – ATM users
- Online users
- Application programmers
- Sophisticated users
- DBA
Advantages of DBMS
- Controlling redundancy
- Integrity can be enforced
- Inconsistency can be avoided
- Data can be shared
- Standards can be enforced
- Restricting unauthorized access
- Solving enterprise requirement
than individual requirement
- Providing backup and recovery
- Cost of developing and
maintaining system is lower
- Data model can be developed
- Concurrency control
- Disadvantages of DBMS
- Complexity
- Size
- Performance
- Higher impact of failure
- Cost of DBMS
- Additional hardware cost
- Cost of conversion
Comparison of file management system with DBMS
Refer below video:
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