Database architecture and modelling
3 Tier Architecture:- a 3tier architecture separates its tiers from each other based on the complexity of the users and how the use the data present in the database . It is the most widely used architecture to design a DBMS at this tier the database resides along with query processing language .
3 Tier architecture complete in 3 level first is external level ,second is conceptual level and third is physical level
(1) external label:- the external level is closest to the users . it is concerned with the way .the data is viewed by individual users .
We can say that external level is the individual user level. Each external view describe that a particular user group is instreated in and hides the rest of the database from that user group .
(2) conceptual level /logical level :- the middle level in the 3tier architecture is a conceptual view label which is also referred to as logical view label its describes that entities structure of data base such as attributes, data types ,relationship and user operation .
(3) physical level :- this is the lowest level of data abstraction it describes how data is actually stored in the database .
We can get the complex Data Structure details at this level.
It is stored in the form of BITS with the physical address on the secondary storage device. It can be view in the the form of files.
Database user :-
(1) DBA[data base administrator]:-
** DBA is a person who is responsible for managing the overall database management system .
** DBA is the leader of the database it is like a user of the system.
** DBA is responsible for administration of all the three levels of the database .
Role of DBA
(1) define schema :- the original database schema is created by writing a set of definition which are translated by the DDL (data definition language) compiler two set of tables that are permanently store in the data dictionary. That are permanently stored in the data dictionary
(2) storing structure and access method definition:- appropriate storage structure and access method are created by DBA . Which are translated by the data storage and definition language compiler .
(3) routine maintenance:- the DBA is responsible for defining procedures to recover data from failures due to human ,natural or hardware function with the minimum less.
This recovery procedure would this enables and organisation to continue working with the available in fact portion of the database .
*Granting of authorisation for data access :-DBA also maintenance that the database is not accessible to unauthorised users .
The DBA is responsible for granting permission to use the data base and store the profile of each user of a database .
The user profile can be used by the DBA to verify that a particular user use only allowed to perform a given operation on the database with the in the limited time frame.
*Database designer:- database designer design the appropriate structure for the database where we share data.
Database design means to design the logical and physical structure of data. Store in the database to meet required information needed for different application.
(1) require collection and analysis
(2) conceptual database design
(3) physical database design
(4) system analyst
(5) application programmer
(6) sophisticated user
Various type of DBMS
(1) Hierarchical DBMS
(2) network DBMS
(3) object oriented DBMS
(4) distributed DBMS
(1) Hierarchical DBMS:- DBMS based on the hierarchical data model are known as H DBMS.
Hierarchical data model was developed by IBM in 1968 and introduce information management system (IMS)
This model is like structure of tree with the records forming the notes and Fields forming the brancmes of the tree .
(2) network data model:- in network database model a record type can have multiple owners.
The network database model is design with the concept of parents and children with their features and relationship.
The linkage or relationship between parents and children upside down tree structure is used.
(3) object oriented database model:- object oriented database model are dependent on the object oriented programming approach. that enables to create classes organise of object structure and inheritance hierarchical and call method of other classes .
(4) distributed database model:-collection of multiple database logical related database distributed over a network is called distributed database model.
Some organisation is used Distributed Data based system rather than centralised database system . A distributed database system stored in several computer. the computers in a distributed system communicate and exchange data among one other using list leased lines.
Features of distributed database model
(1) it is a collection of logically related store data
(2) data in DBMS is spill into number of fragments.
(3) fragments can be replicated in a distributed system
(4) fragment allocated to different site.
(5) in distributed system sites are linked by the communication network.
(6) each DBMS in a distributed system must have at least one Global application.
Unit 2 complete
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Gautam kumar
3 Tier Architecture:- a 3tier architecture separates its tiers from each other based on the complexity of the users and how the use the data present in the database . It is the most widely used architecture to design a DBMS at this tier the database resides along with query processing language .
3 Tier architecture complete in 3 level first is external level ,second is conceptual level and third is physical level
(1) external label:- the external level is closest to the users . it is concerned with the way .the data is viewed by individual users .
We can say that external level is the individual user level. Each external view describe that a particular user group is instreated in and hides the rest of the database from that user group .
(2) conceptual level /logical level :- the middle level in the 3tier architecture is a conceptual view label which is also referred to as logical view label its describes that entities structure of data base such as attributes, data types ,relationship and user operation .
(3) physical level :- this is the lowest level of data abstraction it describes how data is actually stored in the database .
We can get the complex Data Structure details at this level.
It is stored in the form of BITS with the physical address on the secondary storage device. It can be view in the the form of files.
Database user :-
(1) DBA[data base administrator]:-
** DBA is a person who is responsible for managing the overall database management system .
** DBA is the leader of the database it is like a user of the system.
** DBA is responsible for administration of all the three levels of the database .
Role of DBA
(1) define schema :- the original database schema is created by writing a set of definition which are translated by the DDL (data definition language) compiler two set of tables that are permanently store in the data dictionary. That are permanently stored in the data dictionary
(2) storing structure and access method definition:- appropriate storage structure and access method are created by DBA . Which are translated by the data storage and definition language compiler .
(3) routine maintenance:- the DBA is responsible for defining procedures to recover data from failures due to human ,natural or hardware function with the minimum less.
This recovery procedure would this enables and organisation to continue working with the available in fact portion of the database .
*Granting of authorisation for data access :-DBA also maintenance that the database is not accessible to unauthorised users .
The DBA is responsible for granting permission to use the data base and store the profile of each user of a database .
The user profile can be used by the DBA to verify that a particular user use only allowed to perform a given operation on the database with the in the limited time frame.
*Database designer:- database designer design the appropriate structure for the database where we share data.
Database design means to design the logical and physical structure of data. Store in the database to meet required information needed for different application.
(1) require collection and analysis
(2) conceptual database design
(3) physical database design
(4) system analyst
(5) application programmer
(6) sophisticated user
Various type of DBMS
(1) Hierarchical DBMS
(2) network DBMS
(3) object oriented DBMS
(4) distributed DBMS
(1) Hierarchical DBMS:- DBMS based on the hierarchical data model are known as H DBMS.
Hierarchical data model was developed by IBM in 1968 and introduce information management system (IMS)
This model is like structure of tree with the records forming the notes and Fields forming the brancmes of the tree .
(2) network data model:- in network database model a record type can have multiple owners.
The network database model is design with the concept of parents and children with their features and relationship.
The linkage or relationship between parents and children upside down tree structure is used.
(3) object oriented database model:- object oriented database model are dependent on the object oriented programming approach. that enables to create classes organise of object structure and inheritance hierarchical and call method of other classes .
(4) distributed database model:-collection of multiple database logical related database distributed over a network is called distributed database model.
Some organisation is used Distributed Data based system rather than centralised database system . A distributed database system stored in several computer. the computers in a distributed system communicate and exchange data among one other using list leased lines.
Features of distributed database model
(1) it is a collection of logically related store data
(2) data in DBMS is spill into number of fragments.
(3) fragments can be replicated in a distributed system
(4) fragment allocated to different site.
(5) in distributed system sites are linked by the communication network.
(6) each DBMS in a distributed system must have at least one Global application.
Unit 2 complete
Download the app Tech2gautam
App link is below.
App link :-https://www.mediafire.com/file/kgt31vbkfdprfv8/_Tech2gautam_8975115.apk/file
Please download the app for get new notifications on your mobile.
Tags:
DBMS