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databases Online Quiz - 33

Description: databases Online Quiz - 33
Number of Questions: 20
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Tags: databases
Attempted 0/20 Correct 0 Score 0

Students -------------< Cars, This graphic indicates

  1. that a student can own 0, 1 or many cars

  2. a car can be owned by many students

  3. a student cannot own a car

  4. a stundent can own many cars and a car can be owned by many students


Correct Option: A

What is a 'tuple' ?

  1. another name for the key linking different tables in a database

  2. another name for a table in an RDBMS

  3. an attribute attached to a record

  4. a row or record in a database table


Correct Option: D

A detailed, logical, and graphical representation of the entities, associations, and data elements for an organization or business area best describes:

  1. logical model

  2. data flow diagram

  3. entity-relationship diagram

  4. data tree


Correct Option: C

What is a schema ?

  1. A diagram showing the domains of all attributes in the data model

  2. A schedule of data modeling steps

  3. A plan of action for database design

  4. A diagram showing the flow of data in an application

  5. A graphical or language representation of a data model or database


Correct Option: E

AI Explanation

To answer this question, you need to understand the concept of a schema. Let's go through each option to understand why it is correct or incorrect:

Option A) A diagram showing the domains of all attributes in the data model - This option is incorrect because a schema does not specifically refer to a diagram showing the domains of all attributes in the data model. While a schema may include information about attribute domains, it is not limited to just this aspect.

Option B) A schedule of data modeling steps - This option is incorrect because a schema is not a schedule of data modeling steps. A schema is a representation of a data model or database, not a schedule or plan.

Option C) A plan of action for database design - This option is incorrect because a schema is not a plan of action for database design. It is a representation of the database structure or data model, not a plan for how to design the database.

Option D) A diagram showing the flow of data in an application - This option is incorrect because a schema is not specifically a diagram showing the flow of data in an application. While a schema may include information about data flow, it is not limited to just this aspect.

Option E) A graphical or language representation of a data model or database - This option is correct because a schema is indeed a graphical or language representation of a data model or database. It describes the structure and organization of the data, including tables, columns, relationships, and constraints.

The correct answer is Option E. This option is correct because it accurately describes what a schema is, which is a graphical or language representation of a data model or database.

  1. Data about data

  2. Describe a data dictionary

  3. Self-describing

  4. Includes user data

  5. Supports its own structure


Correct Option: D
  1. Logical Data Model

  2. Physical Data Model

  3. Network Data Model

  4. Conceptual Data Model


Correct Option: D
  1. a key that contains only a single field

  2. a key field

  3. a numerical field

  4. a single valued field


Correct Option: D

The ER Model is meant to

  1. replace relational design

  2. be close to a users perception of the data

  3. enable detailed descriptions of data query processing

  4. enable low level descriptions of data


Correct Option: B
  1. system planning and selection

  2. systems design

  3. systems analysis

  4. systems implementation and operation

  5. systems evaluation


Correct Option: C

The data modeling perspective that derives the business rules for a data model from an intimate understanding of the nature of the business, rather than from any specific information requirements in screens, reports, or business forms, is referred to as the:

  1. top-down approach

  2. bottom-up approach

  3. overview approach

  4. business approach

  5. conceptual approach


Correct Option: A
  1. is achieved using an information flow digram

  2. uses a dataflow diagram

  3. is necessary to remove database anomalies through normalization

  4. is the same as process modelling

  5. is all of the above


Correct Option: C

create table Purchaser{ name string, credit_card integer (primary key), address string } create table Product{ product_id integer (primary key), product_name string } create table Purchaser_Product{ credit_card integer, product_id integer, purchase_date date } Based on the sample code above, what is the primary key in the Purchaser_Product table?

  1. purchase_date

  2. credit_card

  3. null

  4. credit_card & product_id

  5. product_id


Correct Option: D

What is an alternate key?

  1. The relationship between more than one entity which has more than one attribute

  2. An attribute that cannot easily identify a record, but can easily viewed as a field

  3. An attribute, other than primary key, that can be used to identify an instance of an entity

  4. A non-distinguishable primary key which is not used to identify fields or records

  5. A primary key with two or more columns on a non-clustered index


Correct Option: C
  1. An ER model is concerned primarily with a physical implementation of the data and secondly with a logical view

  2. An ER model provides a view of the logic of the data and not the physical implementation

  3. An ER model is concerned primarily with a logical view of the data and secondly with the physical implementation

  4. An ER model is entirely concerned with modelling the physical implementation


Correct Option: B

If a key from a parent entity migrates into the primary key of the child entity, what type of relationship is formed?

  1. Non-identifying

  2. Normalizing

  3. Categorizing

  4. Identifying

  5. Emphasizing


Correct Option: D

What can a mandatory one to one relationship indicate?

  1. More entities are needed

  2. The model should be denormolized

  3. The tables are not properly indexed

  4. The model cannot be implemented physically

  5. More attributes are needed


Correct Option: E
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