EER to Relational Model Flashcards
1
Q
Tuple
A
One row of a relation
2
Q
Attribute
A
One column of a relation
3
Q
Relation
A
An entire table of related attributes
4
Q
Domain of an Attribute
A
All the possible values an attribute is allowed to have
5
Q
Table is a:
A
Relation
6
Q
Column Header is a:
A
Attribute
7
Q
All possible column values are:
A
Domain
8
Q
Row is a:
A
tuple
9
Q
Table Definition:
A
Schema of a relation
10
Q
Populated table:
A
State of the relation
11
Q
SuperKey of R
A
A subset of the relation attributes where all the tuple values must be distinct
12
Q
A key is a:
A
minimal superkey
13
Q
Candidate Keys
A
Unique keys that could have been chosen to be the primary key
14
Q
Primary Key
A
An arbitrarily chosen candidate key (requires uniqueness)
15
Q
ER to Relational Schema:
A
- Map regular entities
Separate attributes - Map weak entities
Weak entities get foreign key of their parent entity - Map M:1 Relationships
the M side gets the foreign key - Map 1:1 Relationships
both sides get the foreign key, ore could merge the
table, or could have an intermediate table - Map M:N relationships
create a new table with the foreign keys - Map multi valued attributes
Create a new table
