Nt1330 Unit 1 Study Guide
Q1. Differences between a file-processing system and a Database management system.
1) A Database is generally used for storing data in a structured way in an efficient manner for insert, update and retrieval of data in well defined formats. On the other hand, in file system the data stored in unstructured manner with an unrelated data.
2) A database management system organizes both physical and logical approach to the data on the other hand file-processing system integrates only the physical access.
3) A database management system is designed to organize multiple users accessing at same time with the same data. a file-processing system is generally designed to allow one or more programs to access different data at the same time.
4) A database management system is implemented to access data in form of queries. File processing system is designed to …show more content…
allow prearranged access to data by compiled programs.
5) Backup and recovery of data can be provided by database management system. Whereas data lost in file system can’t be recovered.
6) Database system has strong logging mechanism and manages concurrency control where as in file system integrity method allows structure does not get corrupt.
7) Data redundancy is controlled in database systems and unauthorized access is secured in database system but not in file system.
Q2. The concept of physical data independence and its importance in database systems. Physical data independence defines that the physical storage structure of a device could be changed without changing the logical schema. Which means conceptual scheme remains unchanged even though the storage space and type of data is changed due to modifications. These modifications to change from sequential to random access files and may add a field to records. Physical data independence is available in most of the database and file system environment in which hardware storage of encoding, adding the records, retrieving the specific location of data on disk and application programs view hides from user
For example in case we want to change in the internal schema like file organization or storage devices or index strategy should be possible without having to change the conceptual schema.
Q3.list five responsibilities of database management system.
The five responsibilities of database management are:
1) Interaction with file manager.
2) Integrity enforcement.
3) Security enforcement.
4) Backup and recovery.
5) Concurrency control.
1) Interaction with file manager: file manager is to provide interaction between user and file to retrieve the data .Without file manager the user cannot retrieve the data 2) Integrity enforcement: data integrity defined to the accuracy, consistency and reliability of data. Which consistency constraints may not be satisfied. For example in a categories table the category name must be unique.
3) Security enforcement: unauthorized users or unintended activity can be avoided due to security enforcement .without accessible permission user cannot access the data. Which low level employees could not able to access the higher level supervisor permission.
4) Backup and recovery: the data recovery process may vary upon circumstances of the data loss. Database management is responsible to backup the copy of data in database in the form physical backup and logical backup .In case of any data loss the database management recover the data which database administrator take care about the backup and recovery
5) Concurrency control: In a multiprogramming where multiple transaction takes place simultaneously, it is important to control the concurrency of transaction which the concurrency is controlled by atomicity and isolation
Q4.five main functions of a database administrator Database administrator: A person or group of persons who has centralized control of the database is referred as database administrator.
They are the responsible to manage the DBMS’s use and also creating, modifying and maintaining the database. Which to ensure the database is functioning properly.
Function of database administrator:
To create Schema definition: It is a database administrator responsible to installation, configuration and upgrading hardware and operating system on given database and also to decide what information to be held in database.
To define the storage structure and access methods : Database administrator decide how the data represented in database and described by writing the storage structure definition and also specify the mapping between storage structure definition and the conceptual
schema
Backup and recovery: Database administrator responsible for developing and implementing backup and recovery plan for database. In an event of damage to the database such as human error or failure in a hardware or operating system.
To grant authorization for data access: Authorization checks and validation procedure may define as logical extension. Which database administrator provides or grant permission to accessible user in order to access data .the DBA must understand the particular security model
To modify the scheme and/or physical organization when necessary: The DBA is responsible for examine the database and identify the parts of system that are slow down and repair them. Which the database server is multiple levels the DBA understand the monitoring tools available in each level.
Q5.Difference between two-tier and three-tier architectures. Which is better suited for Web applications Two –Tier Architecture: Two –Tier Architecture is client-server architecture. This provides direct communication between client and server. The end-user (client) sends request to server and server responds to the request provided by clients by retrieving data from it .It does not contains any intermediate between client and server due this tight coupling two-tier architecture runs fast.
Two- tier architecture consists of two parts:
1. Client Application
2. Database
In client application the client write the programs to store the data in database by using different query languages and which database stores the data in it. The client application acts as front end and database act as backend with depends on hardware’s and servers. The main drawback for two tier architecture is server does not response for multiple requests at the same time which cause a data integrity.
Three- tier architecture:
Three –tier architecture is client server architecture expands to include a middle tier (business layer) .which this middle tier act as mediator between client application and database server by processing some duties by translating client calls into database queries and database queries to client calls.
Three –tier architecture has three tiers:
1) Presentation tier.
2) Application tier.
3) Data tier.
Presentation tier: This is also called Client tier. Which is the top level .client sends request to the server by using application tier(business tier).presentation tier acts as front end. Which display the information provided by the server.
Application tier: this is also called middle tier, business tier .it is the intermediate layer which is used to make communication between client and data tier. Application tier is pulled from presentation tier and perform the application functionality.
Data tier: its acts as a database where information is stored and retrieved. It is independent of application tier and presentation tier
Chapter-2
Q5. Relation, Relationship, Primary key, foreign key, Referential integrity. Relation: defined as row and column for storing data in relational database. It is also known as tables. Relationship: A relationship between two tables .foreign key of one table that references the primary key another table
1) A Database is generally used for storing data in a structured way in an efficient manner for insert, update and retrieval of data in well defined formats. On the other hand, in file system the data stored in unstructured manner with an unrelated data.
2) A database management system organizes both physical and logical approach to the data on the other hand file-processing system integrates only the physical access.
3) A database management system is designed to organize multiple users accessing at same time with the same data. a file-processing system is generally designed to allow one or more programs to access different data at the same time.
4) A database management system is implemented to access data in form of queries. File processing system is designed to …show more content…
allow prearranged access to data by compiled programs.
5) Backup and recovery of data can be provided by database management system. Whereas data lost in file system can’t be recovered.
6) Database system has strong logging mechanism and manages concurrency control where as in file system integrity method allows structure does not get corrupt.
7) Data redundancy is controlled in database systems and unauthorized access is secured in database system but not in file system.
Q2. The concept of physical data independence and its importance in database systems. Physical data independence defines that the physical storage structure of a device could be changed without changing the logical schema. Which means conceptual scheme remains unchanged even though the storage space and type of data is changed due to modifications. These modifications to change from sequential to random access files and may add a field to records. Physical data independence is available in most of the database and file system environment in which hardware storage of encoding, adding the records, retrieving the specific location of data on disk and application programs view hides from user
For example in case we want to change in the internal schema like file organization or storage devices or index strategy should be possible without having to change the conceptual schema.
Q3.list five responsibilities of database management system.
The five responsibilities of database management are:
1) Interaction with file manager.
2) Integrity enforcement.
3) Security enforcement.
4) Backup and recovery.
5) Concurrency control.
1) Interaction with file manager: file manager is to provide interaction between user and file to retrieve the data .Without file manager the user cannot retrieve the data 2) Integrity enforcement: data integrity defined to the accuracy, consistency and reliability of data. Which consistency constraints may not be satisfied. For example in a categories table the category name must be unique.
3) Security enforcement: unauthorized users or unintended activity can be avoided due to security enforcement .without accessible permission user cannot access the data. Which low level employees could not able to access the higher level supervisor permission.
4) Backup and recovery: the data recovery process may vary upon circumstances of the data loss. Database management is responsible to backup the copy of data in database in the form physical backup and logical backup .In case of any data loss the database management recover the data which database administrator take care about the backup and recovery
5) Concurrency control: In a multiprogramming where multiple transaction takes place simultaneously, it is important to control the concurrency of transaction which the concurrency is controlled by atomicity and isolation
Q4.five main functions of a database administrator Database administrator: A person or group of persons who has centralized control of the database is referred as database administrator.
They are the responsible to manage the DBMS’s use and also creating, modifying and maintaining the database. Which to ensure the database is functioning properly.
Function of database administrator:
To create Schema definition: It is a database administrator responsible to installation, configuration and upgrading hardware and operating system on given database and also to decide what information to be held in database.
To define the storage structure and access methods : Database administrator decide how the data represented in database and described by writing the storage structure definition and also specify the mapping between storage structure definition and the conceptual
schema
Backup and recovery: Database administrator responsible for developing and implementing backup and recovery plan for database. In an event of damage to the database such as human error or failure in a hardware or operating system.
To grant authorization for data access: Authorization checks and validation procedure may define as logical extension. Which database administrator provides or grant permission to accessible user in order to access data .the DBA must understand the particular security model
To modify the scheme and/or physical organization when necessary: The DBA is responsible for examine the database and identify the parts of system that are slow down and repair them. Which the database server is multiple levels the DBA understand the monitoring tools available in each level.
Q5.Difference between two-tier and three-tier architectures. Which is better suited for Web applications Two –Tier Architecture: Two –Tier Architecture is client-server architecture. This provides direct communication between client and server. The end-user (client) sends request to server and server responds to the request provided by clients by retrieving data from it .It does not contains any intermediate between client and server due this tight coupling two-tier architecture runs fast.
Two- tier architecture consists of two parts:
1. Client Application
2. Database
In client application the client write the programs to store the data in database by using different query languages and which database stores the data in it. The client application acts as front end and database act as backend with depends on hardware’s and servers. The main drawback for two tier architecture is server does not response for multiple requests at the same time which cause a data integrity.
Three- tier architecture:
Three –tier architecture is client server architecture expands to include a middle tier (business layer) .which this middle tier act as mediator between client application and database server by processing some duties by translating client calls into database queries and database queries to client calls.
Three –tier architecture has three tiers:
1) Presentation tier.
2) Application tier.
3) Data tier.
Presentation tier: This is also called Client tier. Which is the top level .client sends request to the server by using application tier(business tier).presentation tier acts as front end. Which display the information provided by the server.
Application tier: this is also called middle tier, business tier .it is the intermediate layer which is used to make communication between client and data tier. Application tier is pulled from presentation tier and perform the application functionality.
Data tier: its acts as a database where information is stored and retrieved. It is independent of application tier and presentation tier
Chapter-2
Q5. Relation, Relationship, Primary key, foreign key, Referential integrity. Relation: defined as row and column for storing data in relational database. It is also known as tables. Relationship: A relationship between two tables .foreign key of one table that references the primary key another table