Chapter 8 - Attribute Data and Tables

Question 1

These are non-spatial properties of surface features

Answer 1

Attributes

Question 2

Attributes are stored in these

Answer 2

Attribute tables

Question 3

Both of these types of data can have attributes

Answer 3

Vector and raster

Question 4

What are two types of linkages of spatial and attribute components?

Answer 4

One-to-one or many-to-one

Question 5

GIS attribute tables are typically stored in this

Answer 5

Database

Question 6

Databases provide means for these two data functions

Answer 6

Data storage/management and data retrieval/analysis

Question 7

What are four types of database models?

Answer 7

1. Flat file; 2. Network; 3. Hierarchical; 4. Relational

Question 8

This is the most common type of database used today

Answer 8

Relational database

Question 9

In what year were relational databases introduced?

Answer 9

1968

Question 10

What are three advantages of relational databases?

Answer 10

1. More flexible; 2. Easy to create/maintain; 3. Easy to understand

Question 11

What is a disadvantage of relational databases?

Answer 11

Slower processing (less of a problem now that computers are faster)

Question 12

Databases are made of these tables

Answer 12

Cross-linked data tables

Question 13

This is another term for tables

Answer 13

Relations

Question 14

What are two terms for table rows?

Answer 14

Records or tuples

Question 15

A record is a set of these for an entity

Answer 15

Attributes

Question 16

What are two terms for columns?

Answer 16

Attributes or items

Question 17

These are descriptive variables for surface features

Answer 17

Attributes

Question 18

These are one or more columns used to index records

Answer 18

Keys

Question 19

These link multiple tables together

Answer 19

Keys

Question 20

This is a form of computer science logic

Answer 20

Relational algebra

Question 21

Relational algebra is the basis for manipulating this

Answer 21

RDB data

Question 22

How many operators does relational algebra use?

Answer 22

8

Question 23

Relational algebra operators use one or more of these to create a new one

Answer 23

Tables

Question 24

What are at least five of the eight relational algebra operators?

Answer 24

1. Restrict; 2. Project; 3. Product; 4. Divide; 5. Union; 6. Intersect; 7. Difference; 8. Join (relate)

Question 25

This relational algebra operator provides a subset of a table by rows

Answer 25

Restrict

Question 26

This relational algebra operator provides a subset of a table by columns

Answer 26

Project

Question 27

This relational algebra operator provides a table with all possible combinations

Answer 27

Product

Question 28

This relational algebra operator provides the inverse of a product

Answer 28

Divide

Question 29

This relational algebra operator combines tables top to bottom

Answer 29

Union

Question 30

This relational algebra operator finds overlap in rows between tables

Answer 30

Intersect

Question 31

This relational algebra operator finds non-overlap in rows between tables

Answer 31

Difference

Question 32

This relational algebra operator combines tables using a key column

Answer 32

Join (relate)

Question 33

These select records based on some criteria

Answer 33

Database queries

Question 34

What are two types of database queries?

Answer 34

Simple query and compound query

Question 35

In this type of database query, selection is based on a single criteria

Answer 35

Simple query

Question 36

What symbols are used in simple queries?

Answer 36

=, <>, >, <

Question 37

In this type of database query, selection is based on multiple criteria

Answer 37

Compound query

Question 38

Compound queries use chain criteria with these three words

Answer 38

And, or, not

Question 39

Compound queries use these operators

Answer 39

Boolean operators

Question 40

These index table records and link different tables

Answer 40

Database keys

Question 41

This is an attribute or combination of attributes that uniquely identifies a record

Answer 41

Superkey

Question 42

There are none of these in superkeys

Answer 42

Null values

Question 43

Is a set of attributes containing a superkey also considered a superkey?

Answer 43

Yes

Question 44

Can a table have multiple superkeys?

Answer 44

Yes

Question 45

This is a minimal superkey that has the fewest number of attributes that ID a record

Answer 45

Candidate key

Question 46

This is a single candidate key chosen to identify and access records

Answer 46

Primary key

Question 47

May primary key attributes have null values?

Answer 47

No

Question 48

These are attribute fields in a table that match a primary key of another table

Answer 48

Foreign key

Question 49

Foreign keys are used to do this

Answer 49

Cross-reference tables