Databases and Distributed Systems Flashcards

1
Q

Acceptance Testing

A

will be carried out by the customer. They will test that a system meets their requirements. If the system passes this test the customer will sign-off the system as being ready for deployment into production running

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

ACID Properties

A

atomicity, consistency, isolation, durability

ensure database operations execute properly without errors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Attribute

A

a feature of an entity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Automated Testing

A

where computer-controlled equipment tests programs for functionality and performance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Automatic Formatting of Code

A

automatically formats code in the right way, for example, automatically indenting code

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Big Data

A

data too large to process via traditional means, with main characteristics being volume, velocity and variability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Binary File

A

stores data in non-human readable format

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Bill Inmon

A

father of the data warehouse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Black-Box Testing

A

a test technique in which the test feeds specific pieces of data into a system, before looking for expected outcome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Branch

A

requests and independent line of development that stems from a central database

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Break Points

A

causes the program to run up to a point and then pause, allowing for variable inspection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Business Modelling

A

proposed plans can use past data to model outcomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Check In

A

involves uploading a modified file after making changes locally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Check Out

A

refers to process by which a developer or user acquires a copy of a specific version of a file

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Code Repository

A

these hold libraries of reusable code or data

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Commodity Clustering

A

the process of constructing a ‘cluster’ from a set of processing nodes integrated via one or more interconnection networks and secondary storage, giving the illusion of a single computer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Composite Key

A

set of two or more fields that together uniquely identify each record in a table

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Conceptual Model

A

a representation of the data requirements of an organisation constructed in a way that is independent of any software that is used to construct the database

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Concurrency

A

a unique characteristic enabling two or more users to retrieve information from the database at the same time without affecting database integrity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

CASE

A

Computer-Aided Software Engineering

the name given to a range of software tools that aid the design, development and testing of different types of software

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Lower CASE

A

provides support in the later stages such as testing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Upper CASE

A

provide support for the early stages of the system’s development life cycle, providing support for stages such as design

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Data

A

a set of raw facts and figures with no apparent meaning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Database

A

a structure collection of data

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Database Administrators

A

specially trained people to install and manage databases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Database Management System (DBMS)

A

a software system that enables the definition, creation and maintenance of a database and which provides controlled access to the database

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Data Dictionary

A

a collection of data and attributes about data elements that are being used in a database, describing the meanings and purpose of data elements within the projects context and provides guidance on interpretation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Database Integrity

A

how accurate a database is, questioned in flatfile databases, because if one entity changes, multiple records have to be changed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Database Method

A

because all access to the database is under DBMS, all data is under centralised control, so the system is program-data independent, making it easier to control access to data, backup data and access data and create new applications

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Database Normalisation

A

a database design tool used to optimise database design by turning flat-file databases into relational databases and optimising their design

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

First Normal Form

A

where each entity has a primary key value and no repeating groups of data

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Second Normal Form

A

based on full-functional dependencies, where entities are already in first normal form and all attributes are dependent on the primary key

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Third Normal Form

A

entities must be in second form with no transitive dependencies removed meaning non-key items must not depend on other non-key items

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Database Schema

A

a definition of the database in a formal language that is used by the DBA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Conceptual Schema

A

the overall database structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Logical Schema

A

tables, fields and relationships

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Physical Schema

A

every part of the database including files and storage details, contains the whole database

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Sub-Schemas

A

contains a subsection of the physical schema, holding the entities that a particular user needs to have access to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Database Triggers

A

modules of code stored in the data dictionary that runs when associated events occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Data Constraints

A

describe rules which apply to data

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Data Mart

A

are often smaller than data warehouses with fewer data sources and do not have as long life space; they are often project focused with limited use and are often terminated once a project is finished

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Data Mining

A

the process of searching and analysing a large batch of raw data in order to identify patterns and extract useful information

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Data Model

A

a method of describing the data, its structure, its relationships and its constraints that apply to the data for a given system or organisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Data Redundancy

A

where data is unintentionally duplicated, reduced in databases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Data Requirements

A

states which data needs to be stored

46
Q

Data Warehouse

47
Q

DBMS Layer

A

acts as a layer of software between all the users and the database

48
Q

DDL

A

Data Description Language

used to control the structure of the database, to creawte new entities, attributes, keys and relationships, and give access rights to users

49
Q

Degree of Relationship

A

between two entities, refers to the number of entity occurrences of one entity which are associated with just one entity occurrence of the other and vice versa

50
Q

Deletion Anomalies

A

occur when information is lost because a single record is removed from the fact-file

51
Q

Distributed Processing

A

involves distributing and processing big data across multiple nodes through parallel processing, therefore making data processing and analysis significantly faster and more efficient

52
Q

DML

A

Data Manipulation Language

controls data within the database, carrying out four basic functions: appending, deleting, amending and retrieval

53
Q

Entity

A

the thing you are collecting data about

54
Q

Entity Relationship Diagram (ERD)

A

shows how different entities relate to each other in an application or database

55
Q

Field

A

a single piece of information which is stored within a row, for example, first name, email, date of birth

56
Q

File

A

a data structure that is always stored on a device that is a collection of records

57
Q

Flatfile Database

A

one spreadsheet with one table, eg Excel

58
Q

Foreign Key

A

a field in one table that is a primary key in another table and is used to create a link between these tables

59
Q

Fully Functional Backup

A

occurs in second normal form where all entities must be in first normal form and all partial key dependencies

60
Q

Hierarchical Database

A

a data model where the database is arranged into a parent-child structure

61
Q

Horizontal Scaling

A

the process of adding more machines or nodes to a resource pool in a system to distribute the workload

62
Q

Information

A

data with meaning

63
Q

Inheritance

A

the relationship between two object types in which one is a kind of the other and shares some of its properties or behaviours

64
Q

Integrated Data

A

where data is collected from a range of sources, transformed into common format, then loaded into the warehouse, integrating data into a single source

65
Q

Locking

A

where the DBMS places a lock on the record, giving read/write access rights to the first user who opens the record, and read-only rights to any subsequent user, meaning it is locked until the first user has finished editing it and commits their changes to the database

66
Q

Logical Model

A

specifies the entities we are storing data on: their attributes and the degree of the relationships between the entities

67
Q

Manual Testing

A

where a person manually tests programs for functionality and performance

68
Q

Memory Protection

A

a way to control memory access rights to a computer, where RAM is set up so that, by default, it cannot access various pieces of data without causing a memory error so that two programs cannot use the same memory location

69
Q

Merging

A

joining data from multiple sources

70
Q

Multi-Transactions

A

consists of multiple, interdependent transactions spread across different databases and systems, eg transferring money from one account to another

71
Q

Network Database

A

represents data in a tree-like structure, where pointers connect records in a network or graph structure

72
Q

Normalised Entity

A

a set of entities that contain no redundant data

73
Q

ODBC

A

Open Database Connectivity

a protocol applied to databases allowing a database made using one piece of database software to be viewed using another piece of database software, using an open standard Application Program Interface so the database can be used in another application

74
Q

OODB

A

Object-Oriented Database

the same concepts applied to Object-Oriented Languages can be applied to databases, so data is stored within objects along with the methods and processes that will be carried out on the data

75
Q

OS Authentication

A

where authentication is delegated to the OS

76
Q

Performance Testing

A

carried out to ensure that a system will be able to cope with the required workload

77
Q

Physical Model

A

adds detail to allow the data model to be implemented with a specific DBMS

78
Q

Primary Key

A

a single field that acts as a unique identifier for each record in a table

79
Q

Program-Data Independence

A

where changes to the program design don’t force the data file structure to be changed

80
Q

Record

A

a collection of data for one item, person or thing

81
Q

Referential Integrity

A

if a value appears in a foreign key in one table it must also appear in the primary key in another table

82
Q

Relation

A

set of attributes and tuples, modelling an entity

83
Q

Relational Database

A

a database where data is held in more than one table, with tables linked together using relationships

84
Q

Relationship

A

a link between two entities, implemented in a database using primary and foreign keys

85
Q

Resource-Related Failures

A

where the program runs out of memory or requires external files that are missing or inaccessible

86
Q

Roll-Back

A

allows software developers to undo changes made to a system and revert back to a previous version

87
Q

Run-Time Diagnostics

A

this creates a virtual machine that emulates a system that the program is designed for when it’s not specifically designed for that platform

88
Q

Schemas

A

a collection of database objects

89
Q

Screen Design Software

A

allows the design of screens

90
Q

Secondary Key

A

any index that is not the primary key

91
Q

Shared Memory

A

where memory protection does not occur but may lead to memory corruption if it is not made read-only

92
Q

Single Transaction

A

refers to a series of one or more database operations resulting in one action, completed successfully, such as withdrawing money from an ATM

93
Q

Software Engineering

A

an engineering approach to software development and is the process of designing, developing, testing, and maintaining software systems, different to programming due to the focus on engineering, so a software engineer will involve more mathematic and scientific methods

94
Q

Step Through

A

steps through program one statement at a time, allowing faults in program logic to be identified

95
Q

Strategic Planning

A

a use for data warehousing, involves knowing past sales patterns, in order to plan ahead eg buying in stock, advertising campaigns and promotions

96
Q

Subject Oriented

A

when a data warehouse is used to analyse a particular subject area

97
Q

Syntax Highlighting

A

displays code in different colours and fonts according to categories of terms

98
Q

System Testing

A

often carried out by a specialist testing team, who will check that the system as a whole works as required. System testers will not usually be involved in the development of individual programs

99
Q

Table

A

collection of related data made up of fields and records

100
Q

Tagging Version

A

allows developers to assign a label to a specific point in history, serving as a reference point

101
Q

Text File

A

shares data in human readable format

102
Q

Transaction

A

this represents a change in the database, providing reliable units of work to allow database recovery and provide isolation between programs accessing a database concurrently

103
Q

Transitive Dependencies

A

means there must be no unique associations between attributes in the record that are not used as a primary key

104
Q

Unit Testing

A

often performed by the developer, and check that a program functions as required

105
Q

Unproductive Maintenance

A

where changes to program design force the data file structure to be changed, occurs in factfiles

106
Q

Update Anomaly

A

occurs in flatfiles where records are not correctly updated causing data corruption and reducing data integrity

107
Q

Variable Watch

A

the act of observing a specific variable whilst the program runs, which the programmer can do whilst using variable inspection

108
Q

Version Numbers

A

where previous versions are numbered in order to keep track of the current version

109
Q

Vertical Scaling

A

the process of increasing power to individual machines in the system

110
Q

Warning Messages

A

allow early detection of issues such as unused variables optimising performance

111
Q

Whitebox Testing

A

tester will feed data into a system that ensure that all path through the code are used and therefore testing

112
Q

Wire-Framing Software

A

help map out the user experience, layout, and overall flow, streamlining the design process