Category: DDD FUNDAMENTAL



 

1. Short note: database, data, application, metadata, RDBMAS, data integrity.

Database: A collection of information, preferably related information, and preferably organized.

Data: A term applier to organized information.

Application: A front end tool used by developers, in-house staff, and-users to access a database.

Metadata:  data is the data about the data.

RDBMS: Relational database management system.

Data integrity: The validity of data is called Data integrity.

 

2. Name the different type database.

Ans: Three type of database are available.

1. Transactional.

2. Decision support system (DSS).

3. Hybrid.

 

3. What do you mean by transitional database?

Ans: A transactional database is a based on small change to the database. Two types database are Client server database & OLTP database.

 

4. What is database modeling? Write down the different database model techniques?

Ans: A model used to organized and apply structure to other disorganized information.

The different database model techniques are 1. File system 2.Hierarchical 3.Network 4.Relational 5.Object 6. Object-Relational

 

4. What are the methods you have to follow to design a database?

1. Requirement analysis.

2. Conceptual design

3. Logical design

4. Physical design

5. Tuning phase

 

5.What are business rules? Write down the aspects of business rule.

Business rule: business rules for an organization are the process & flows  whatever is involved in daily working activities of that organization.

Aspects of business rules are:

1.any types of organization policies.

2.any types of calculation or formula.

3.any types of regulation.

 

6.What is data type? Write down the sections of data type.

 Data type: Data   type restrict the values in the fields.

Sections of data types  are :1.simple  data  type ,  2.complex data type,3.spealized data type.

7.What  is constraints? Give some examples

Constraint: Constraints  restricts the values that are allowed in the table fields.

Some of examples of constrains are  Not null, validation  check , keys.

 

8. Shortly brief the key constrain.

Key  constraint: Key constraints  include the primary keys ,foreign keys ,unique keys .Key constraints allow the checking and validation of values between  the fields in different tables. Primary keys and foreign   keys are used in relationships between the parent tables and child tables.

 

9.What is normalization? Write down its benefits.

Normalization  : Normalization removes the duplication of data  minimize the chunk of redundant

Benefits of normalization:

(1).physical space is reduced

(2).Data becomes best organized .

(3).A single table record is updated.

10.What are difference  between primary key & unique key?

Ans: primary keys:- A primary key is used to uniquely identify a record in a table .A primary key doesn’t allow  duplicate & null value.

Unique keys:- A unique key is created on a field containing only unique values trough out an entire table. Unique keys allows null value.

 

11.Shortly brief : view, index, PK ,UK & FK.

Ans:view :-A logical overlay containing a query , executed whenever the view is accessed . Repeated query execution can make views very inefficient in busy environment.

Index:- An index is usually a copy of a very small section of table , such as  a single field & short length field.

PK:- A primary key is used to uniquely identify a record in a table .A primary key doesn’t allow  duplicate & null value.

UK:- A unique key is created on a field containing only unique values trough out an entire table. Unique keys allows null value.

FK:-  A foreign key define the reference for each record in the child table , referencing back the primary key in the parents table.

12.What do mean by functional dependency?

Functional dependence: “Y” is functionally dependent on ” X”  if the value of  “Y”  is determined by “X”.  in other words if Y=X+1, the value of “X” resultant value of “Y”

 

13.What is SQL?

Ans: SQL means that structure Query Language. It used to access data in a relational database.

Write down the different types of Query Commands and change commands.

14.Write down different types of query commands & data changes commands.

Query commands:- 1.Basic query 2. Filtered query 3. Sorted query 4. Aggregated query 4. Join query 5. Nested query 6. Composite query

Data change commands:- Insert, Update, Delete

 

15.Define shortly : Nested quire, composite query.

Nested quire: A nested query is also know as a sub query, which is a query contained within another query.

Composite query: A composite query is a query that merges multiple query results together, most often using the UNION keyword.

 

16.Define shortly: Inner join, Cross join, Outer join and self join?

Inner join: An intersection between two table using matching field values. Retuning records common to both tables only.

Cross join: This is also known mathematically as a Cartesian product. A cross join merges all records in one table with all records in another table, regardless of any matching values.

Outer join: An intersection plus rows outside the intersection, in one table and not in the other table of a join.

self join: A self join simply joins a table to itself, and is commonly used with a table containing a hierarchy of records.

 

17. Write down the demoralization Tricks?

Ans: – demoralization Tricks are :

1. Separate active and inactive data.

2. Copy fields between tables.

3. Summary fields in parent tables.

4. Separate heavily and lightly accessed fields.

18. What is a star schema?

Ans: The most effective approach for a data warehouse database model is called a star schema.

19. What is a snowflake schema?

Ans: A data warehouse, single fact table structure with dimension tables in multiple layered hierarchies of dimensional tables.

20. What are fact table and Dimension table?

Fact table: A term generally applying to an unstructured file, such as a text file.

Dimension table: A descriptive or static data table in a data warehouse.

 

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Approaching relational database modeling

A database is a collection of information.

a. True              b. false

2. A database is a structure  object .

  a. True           b. false

3. A data structure object consist of ………. & …………….

Ans:(data , metadata)

4. A   …………restricts values of field. (datatype)

5.The database itself  isn’t stored & executed on a database server computer.(it is stored itself)

a.True                                 b. false

6.GUI means graphical user interface.

a.True             b. false

7. OLTP means online transactional processing.

a.True             b. false

8.The ………….. is also known as  flat files.

Ans:(file systems)

9.File system model take on a child – parent relationship.

Ans:( Hierarchical)

a.True                                b. false

10.Hierachical database model support one to many relationship.

  a.True            b. false

11.Network database model support one to many relationship.

  a.True                             b. false

12.RDBM means ……………………….

Ans:( relational database management system)

13.relational database was invented by Dr.E.F.Codd of IBM.

  a.True            b. false

14.SQL means  …………..

Ans:(structured query  language)

15.Dbas,paradox  is a name of MS Word engins.

a.True                                 b. false

16.An object database model  provides …………dimensional structure.

Ans:(3)

17……………database model is best suited for retrieval of group of data.

Ans:(object –relational )

18.A reporting database containing only active data.

a.True             b. false

18.ERDs means entity relational database.

Ans:( entity relational diagram)

a.True                   b. false

19.DDL means ……………

Ans:(data definition language)

20.File system started  used in pre 1960(1950)

a.True                   b. false

21. Relational model first started from 1970.

a.True                                b. false

22.how many types of database model ?(6)

 

Chapter -2

 

1.Business rules is the processes and flow of whatever is involved in the daily  workings of an organization is ?

A.True       B.False

2.Simple business rules can be implemented in a database model by creating relationships between table is ?

A.True       B.False

3.Black box  implies chunks of code that can function  dependently  is ?

A.True          B.False 

4.Constraints are  things that place restrictions on values stored in a  ——–?

Ans:(Database)

5.A trigger is a chunk of code that executes  when specified event occurs is ?

A.True       B.False

6. The database designer must be _________  , _________and__________?

Ans:(Objective ),(Clinical),(Analytical)

7.Abstraction is a _______or ________process is?

Ans:(Logical ),(Mathematical)

9.Heterogeneous system is a system consisting of similar parts is

A.True            B.False

10.Homogeneous system is a system consisting of similar parts is

A.True       B.false

11.Converting legacy database can often be the most difficult of tasks is

A.True        B.false

CHAPTER  3

1.values in a data base are made up of                  ,and which is essentially                        .

Ans:data,information.

2. ——– is determined by the by integrity of data. (validity)

3.the intrigety of data is the correct from data.
Ans : (a)true ( b)false
4.information is ………..
Ans-knowledge

5. The information is data that is stored in a  data base.(true)

6. data is composed of ………….and ……….item of information.
Ans:  unique,   specifically.

7.  Unique data item values are stored in …………..in database

Ans:  slots

8.programes are set of none precise instructions.

Ans : (a)true ( b)false
9.data type comprise  the forms data can take, such as ……….. , ……….. , ………. And others.
Ans : numbers, dates ,strings.

10.a table is a ……….. in to which data is poured.
Ans : bucket.

11. table contain ……… and ……….
Ans : fields, records.

12. the terms records , raw, and  tuple all mean different thing.
Ans : (a)true ( b)false

13.the terms field, column and attribute all mean the same thing.
Ans : (a)true ( b)false

14.data can subsequently access according to the field structure of the table …………..  by  ……………………
Ans : record by record.

15.a field applies structure and definition to …………….. of data within each ………….
Ans : chunk, repeated record.

16. a constraint ……….. a value.
ans: constrains.

17.ISBN mean……………………
ans: international   standard book number.

18.integer only allow whole number ,all characters of digit between 0 and 9.with no decimal point character.
Ans : (a)true( b)false

19.data type divided into four separate section.
Ans : (a)true ( b)false

20. simple data type apply on …….value.

Ans; single.

21.complex data type include any data type bridging the gap between ……….and …………including item such as ………and …………
Ans: object , relational data base, binary object ,collection arrays,

22. a  string is a sequence of one or more ………..

Ans: characters

23.string can be  …………..or ……….

Ans: fixed length , variable length.

24.Varable would be stored as NY plus a space …………..(charater)

25.Fixed length strings  are more efficient for

Chapter 4 : Understanding Normalization

1.Normalization removes duplication and minimizes redundant———-

Ans: (chunks of data)

2.Normalization is not always the best solution.

Ans: True

3.Normalization is not the____ and_____ of relational database.

Ans: (be-all, end-all)

4.What is intention of relational database?

Ans: eliminate anomalies from a database

5.Two kinds of anomaly ids available.

Ans: false (three)

6.When dose can anomaly can occur?

Ans: During changes to a database.

7.Why anomaly bad thing?

Ans: data can become logically corrupted.

8.What is anomaly?

Ans: anomaly is an erroneous change to data in relational database.

9.Delete anomaly caused when a record is deleted from a_______

Ans:  Master table

10.There are ­­_____,______,_______ types of anomaly.

Ans: Insert anomaly, Delete anomaly, Update anomaly.

11.Insert anomaly caused when __________

Ans: A record is added to detail table with no a record existing in master table.

12.There are _______ kind of dependency.

Ans: seven

13.A candidate key is a field/fields that can act as a _______

Ans: primary key

14.Candidate key also non as ______

Ans: Potential or permissible key.

15.A collection could be an area of values of the different types.

Ans. False

16.BCNF means

Ans. Boyce- Codd normal form

17.PZNF means

Ans. Projection normal form

18.DKNF means

Ans. Domain key normal form.

19.Separation of repeated fields in master detail relationship we can use

Ans. 1 NF

20.Pushing static data into new table we can use

Ans. 2 NF

21.In many to many relationship we can use 3 NF.

Ans. True

22.1 NF can eliminate repeating  groups.

Ans. True

23.  3rd NF can create a new table to contain any separated field.

Ans. True

24.Which the biggest issued with beyond 3NF

Ans. Complexity and performance