Quiz 1.3 Flashcards

1
Q
  1. What is the informal or general definition of a database?
A

Collection of related data (facts about the real world)

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2
Q
  1. Give a more formal definition of a database (include the three key implicit properties we discussed in class)?
A
  • Logically Coherent.
  • My database needs to have a purpose.
  • Representative of the real world.
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3
Q
  1. What is a Database Management System (DBMS)?
A

Piece of software that helps us administrate our data.

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4
Q
  1. What four main actions does the Database Management System (DBMS) help us to facilitate in relation to the database (please complete the actions below as well as providing a short description)?
A

a. D – Define – data types, attribute names, entities (schema) in the database catalog (meta data).

b. C – Construct – file structures, disk, etc… how we represent our data (attributes make the majority of this).

c. M – Manipulate – Query, update, etc… on my database (modifying the state of the database). SQL – DML (Data Manipulation Language).

d. S – Need to make the database available to multiple users (multiuser vs. single user systems).

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5
Q
  1. What two other actions does the Database Management System (DBMS) help us facilitate in relation to the database (please complete the words below ?
A

a. P – Protection, implements RBAC (what is this?).

b. M – Maintain – apply updates to the DBMS software, indexing maintenance, etc…

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6
Q
  1. In the database approach, data types, constraints, and locations of the data are stored where?
A

Database Catalog (Meta data)

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7
Q
  1. This mechanism of storing data (see question 6) separately from the data types, constraints, and locations of the data facilitates this type of data independence or abstraction?
A

Program data independence.

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8
Q
  1. What are the two main properties of a transaction (give a short description of each)?
A

Isolation – as an end user, I need the system to appear as if I’m the only user.
Atomicity – shouldn’t have partial success in manipulation of my database (all pass, or all fail).

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9
Q
  1. What is the name for the combination of the primary database and secondary DBMS & related software?
A

The database system.

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10
Q
  1. The class of users who require access to the database for querying, updating, and generating reports to do their jobs?
A

End Users.

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11
Q
  1. Name three different types of users from the class of users described in question 10 (give a short description for each)?
A
  • Casual (you know the rest)
  • Naïve (Least about the database management system)
  • Sophisticated (Most about the database management system)
    o DBA (Database Admin)
     Database Designer
     Software Engineer
     System Engineer, etc…
  • Standalone
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12
Q
  1. What are three benefits of using a Database Management System (DBMS) over a file-based system?
A

Control data redundancy – each user group might have same representation of student.
- Leads to data inconsistency.
- DOE (Duplication of Effort)
Security – implement more granular access i.e., RBAC, etc…
Ensure data abstraction – i.e., program data independence, method data independence.

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13
Q
  1. When might you choose to use a file based-based system over a Database Management System (DBMS)?
A

Single user system, overhead cost, short timeline.

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14
Q
  1. What law predicts that the number of transistors on a microchip will double every two years?
A

Moore’s law

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15
Q
  1. Describe the difference of horizontal and vertical scalability?
A

Vertical scalability increasing the storage medium space, ram, etc.., horizontal scalability – creating more instances of my databases programs (API).

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16
Q
  1. The module that typically handles user interaction and provides the user-friendly interfaces such as apps for mobile devices, or forms or menu-based GUIs (graphical user interfaces) for PCs.
A

Client Module

17
Q
  1. The module that typically handles data storage, access, search, and other functions.
A

Server Module

18
Q
  1. What is the suppression of details of data organization and storage referred to as (in general)?
A

Data abstraction

19
Q
  1. What is the collection of concepts that can be used to describe the structure of a database referred to as?
A

Data Model

20
Q
  1. What are the three types of general data models (name, and give a short description for each)?
A

Conceptual
Representational
Physical

21
Q
  1. What are the three general components of the Conceptual Data Model (name and give a short description for each)?
A

Entities, attributes, relationships.

22
Q
  1. This is referred to as the “description of the database”, is specified during database design, and is not expected to change frequently?
A

Database Schema

23
Q
  1. What is the data in a database at a particular moment in time referred to as?
A

Database snapshot, database state

24
Q
  1. What is the state of the database called that corresponds to when it satisfies the structure and constraints specified in the schema?
A

Valid state, business rules (business logic) – can’t be enforced by the DBMS.

25
Q
  1. Changes occasionally need to be applied to the schema as the application requirements change, this is referred to as what?
A

Schema Evolution

26
Q
  1. What are the three levels of the three-schema architecture (name, and give a short description for each)?
A

External
Conceptual
Physical

27
Q
  1. What level of the three-schema architecture is the actual data stored at?
A

Physical

28
Q
  1. What is the process of transforming requests and results between levels of the three-schema architecture?
A

Mapping

29
Q
  1. What is data independence (in relation to the three-schema architecture)?
A

The ability to alter one level of the schema, without having to make changes to the other.

30
Q
  1. Define the two types of data independence?
A

Logical data independence – Conceptual + External
Physical data independence – (Physical + (Conceptual + External)).

31
Q
  1. Which type of data independence is harder to achieve and why?
A

Logical data independence – Conceptual + External

32
Q
  1. The high-level DML (Data Manipulation Language) used in a standalone interactive manner is referred to as what?
A

Query language

33
Q
  1. This type of language is used by the DBA and database designers to define the schema.
A

DDL (Data Definition Language)

34
Q
A