Database :
Database is a collection of related data which can be shared by multiple users
Data :
Description of fact
DBMS :
Software used to manage database
DataModel :
Technology used to develop database
Relation:
A table with columns and rows
Attribute
A named column for a relation
Domain :
Set of allowable values for 1/more attributes
Touple :
A record of a relation
Relational Database
Collection of normalized tables
File Mangement System (FMS - Before 1969)
* Before 1969 there was no database concept
* Data are stored in files
* Whenever we need to retrieve data from files , the whole content loaded into memory
Disadvantages
1. Misuse of memory
2. No relation between 2 files
3. No validation of data
4. More redundant data
Hierarchical Database Management System (HDBMS -1969) :
* First time the database concept comes into 1969 by using HDBMS data model
* It was developed by IBM
* It works for relations like 1:1 ,1:M means that the HDBMS datamodel works on parent - child relation
* If data belongs to M-M relation it will not work because one child con't have more than one
parent
Disadvantages
1. Redundant (Duplicate) data
2. Inconsistency (Incorrect) of data
3. Data search based on whole knowledge of data
4. Space misuse due to redundant data
Network Database Management System (NDBMS - 1971) :
* It is replaced of HDBMS by IBM i.e it supports Many - Many relations with same structure of HDBMS
* In this model data linking concept was introduce to manage M:M relations
* so this model was not accepted as efficient model because writing programs becomes more difficulty
Leading RDBMS products available in Market
1. DB2 :
1. IBM people introduced this database
2. DB2 works only on Mainframes
3. Maintenance cost is very high
4. in DB2 the security is very high
2. ORACLE
1. ORACLE Company introduced this database
2. ORACLE is platform independent
3. Every year ORACLE adds some new feautures
3. Sybase
1. It is one of good database , it provides good security
2. Microsoft has given the market to this database
3. It is very famous upto 1994
4. In india NIIT corporation used this database first
5. From 1994 Microsoft stopped to give the market support to this database because Microsoft introduced their own database i.e SQL Server
4.MYSQL
1. It is also similar to SQLSERVER
2. we can download this database from internet with free of cost and we can use
3. Very small organizations or companies using this database because they don't want to spend more money for buying or purchasing
Database is a collection of related data which can be shared by multiple users
Data :
Description of fact
DBMS :
Software used to manage database
DataModel :
Technology used to develop database
Relation:
A table with columns and rows
Attribute
A named column for a relation
Domain :
Set of allowable values for 1/more attributes
Touple :
A record of a relation
Relational Database
Collection of normalized tables
File Mangement System (FMS - Before 1969)
* Before 1969 there was no database concept
* Data are stored in files
* Whenever we need to retrieve data from files , the whole content loaded into memory
Disadvantages
1. Misuse of memory
2. No relation between 2 files
3. No validation of data
4. More redundant data
Hierarchical Database Management System (HDBMS -1969) :
* First time the database concept comes into 1969 by using HDBMS data model
* It was developed by IBM
* It works for relations like 1:1 ,1:M means that the HDBMS datamodel works on parent - child relation
* If data belongs to M-M relation it will not work because one child con't have more than one
parent
Disadvantages
1. Redundant (Duplicate) data
2. Inconsistency (Incorrect) of data
3. Data search based on whole knowledge of data
4. Space misuse due to redundant data
Network Database Management System (NDBMS - 1971) :
* It is replaced of HDBMS by IBM i.e it supports Many - Many relations with same structure of HDBMS
* In this model data linking concept was introduce to manage M:M relations
* so this model was not accepted as efficient model because writing programs becomes more difficulty
Leading RDBMS products available in Market
1. DB2 :
1. IBM people introduced this database
2. DB2 works only on Mainframes
3. Maintenance cost is very high
4. in DB2 the security is very high
2. ORACLE
1. ORACLE Company introduced this database
2. ORACLE is platform independent
3. Every year ORACLE adds some new feautures
3. Sybase
1. It is one of good database , it provides good security
2. Microsoft has given the market to this database
3. It is very famous upto 1994
4. In india NIIT corporation used this database first
5. From 1994 Microsoft stopped to give the market support to this database because Microsoft introduced their own database i.e SQL Server
4.MYSQL
1. It is also similar to SQLSERVER
2. we can download this database from internet with free of cost and we can use
3. Very small organizations or companies using this database because they don't want to spend more money for buying or purchasing
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