What is the software that provides the mechanisms to access a database called? W

Question

1. What is the software that provides the mechanisms to access a database called?
2. What are the three levels of the ANSI SPARC architectures for databases and what are their purposes in a database implementation?
3. What is meant by the term data independence? How is data independence provided in the context of the three-level ANSI SPARC architecture?
4. Name two advantages of using a DBMS for your application rather than building your database from scratch?
5. What is a client/server architecture and how is it used in a database applications. What is a multi-tier client/sever system?
6. What are the major components of a DBMS?
7. What does a relation look like in the relational database model?
8. What is entity integrity in the relational database model and how is it provided by a key?
9. What are the four kinds of keys defined in chapter 4 for the relational database model and how are they related?
10. What is an attribute? What is a tuple? How do these relate to the rows and columns of a relation (a table)?
11. What restrictions are place on relational database relations (tables) in terms of the attributes and tuples?
12. What is a foreign key and how does it provide referential integrity?
13. What are the degree and cardinalityof a relational database relation (table)?
14. What is a relational database view?
15. What are the unary operator of the relational algebra?
16. What are the set operators of the relational algebra and what do they do?
17. What is the purpose of the Cartesianproduct operator of the relational algebra?
18. How is the basic join operator defined? What are the different kind of join operators?
19. How is the division relational algebra operator used?
20. What is the purpose of the aggregateand grouping operators?

1. What is the software that provides the mechanisms to access a database called?
2. What are the three levels of the ANSI SPARC architectures for databases and what are their purposes in a database implementation?
3. What is meant by the term data independence? How is data independence provided in the context of the three-level ANSI SPARC architecture?
4. Name two advantages of using a DBMS for your application rather than building your database from scratch?
5. What is a client/server architecture and how is it used in a database applications. What is a multi-tier client/sever system?
6. What are the major components of a DBMS?
7. What does a relation look like in the relational database model?
8. What is entity integrity in the relational database model and how is it provided by a key?
9. What are the four kinds of keys defined in chapter 4 for the relational database model and how are they related?
10. What is an attribute? What is a tuple? How do these relate to the rows and columns of a relation (a table)?
11. What restrictions are place on relational database relations (tables) in terms of the attributes and tuples?
12. What is a foreign key and how does it provide referential integrity?
13. What are the degree and cardinalityof a relational database relation (table)?
14. What is a relational database view?
15. What are the unary operator of the relational algebra?
16. What are the set operators of the relational algebra and what do they do?
17. What is the purpose of the Cartesianproduct operator of the relational algebra?
18. How is the basic join operator defined? What are the different kind of join operators?
19. How is the division relational algebra operator used?
20. What is the purpose of the aggregateand grouping operators?

Explanation / Answer

database management systems

2. What are the three levels of the ANSI SPARC architectures for databases and what are their purposes in a database implementation?

3 levels are
1) internal
2) conceptual
3) external

internal level - this is the lowest level of data abstraction. it describes how the data are actually stored in storage devices. it deals with data compression and encrypton techniques used

conceptual level - it describes what data is stored in database and what is the relationship between them. database admin, develoers work on this level.

external level - it is the hoghest level of data abstraction. it describes only the part of the entire database that a end user is concern.

3. What is meant by the term data independence? How is data independence provided in the context of the three-level ANSI SPARC architecture?

a database contains lots of data in addition to the user data and is called metadata. it stores data about data to store and locate data modifying the metadata is a tedious job and it need to be changed over time to meet the user expectations. if the entire data is dependent then it will become a tedious job .
medatadata follows a layered architecture, so if the data is changed at one layer then it does not affect the data on other layer.
logical data independence - Logical data is data about database, that is, it stores information about how data is managed inside. For example, a table stored in the database and all its constraints, applied on that relation

Physical Data Independence - all the schemas are logical, and the actual data is stored in bit format on the disk. Physical data independence is the power to change the physical data without impacting the schema or logical data.

4.What are the major components of a DBMS?

1) software - this is the set of programs used to control and manage the overall database. this includes the database management system software, operating system and network software being used to share the data among users and applications program to access the data from the database.
2) hardware - it provides the interface betwene the computers and real world systems.
3) data - data is the main component of the ddbms since user only need to store and retreive the data as and when required.
4) procedures- these are the rules that assist on how to use the dbms and in designing and running the database.
5) database access language - this language is used to access and collect the data stored in the database, user writes a set of appropriate language to execute the query and collect the data
6) query processor - this converts the user query to low level instructions
7) data manager - Also called the cache manger, this is responsible for handling of data in the database, providing a recovery to the system that allows it to recover the data after a failure.
8) Database Engine
The core service for storing, processing, and securing data, this provides controlled access and rapid transaction processing to address the requirements of the most demanding data consuming applications. It is often used to create relational databases for online transaction processing or online analytical processing data.
9) Data Dictionary
This is a reserved space within a database used to store information about the database itself. A data dictionary is a set of read-only table and views, containing the different information about the data used in the enterprise to ensure that database representation of the data follow one standard as defined in the dictionary.

5. What is entity integrity in the relational database model and how is it provided by a key?

entity integrity assures there is no duplicate record is stored within the same table and the field ie. coloumns or group of columns that identifies the record is neither null nor duplicate
for this primary key is used. while creating the table in the database we define the primary key of the table so it's value cannot be null or duplicate
if someone enters the null or duplicate value in the table for the primary key database engine will throw error

6. What is an attribute? What is a tuple? How do these relate to the rows and columns of a relation (a table)?

attributes are columns in the table which describes each tuple.
rows in a table is called tuple or record

7. What is a foreign key and how does it provide referential integrity

A foreign key is a column or set of columns in one table that refer to the primary key of another table.

so when the record is deleted from the parent table then the value corresponing to the primary key in the child table is also needs to be deleted otherwise the error will be returned.

similary when the record is to be inserted in the databas then the value of the foreign key should be present as the primary key in the parent databas eotherwise the error will ve thrown

due to time contraint not able to answer rest ques

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