L1: algebra Flashcards
(12 cards)
1
Q
relationships maintained
A
keys
2
Q
relations
A
entities : single value
column distinct name
row distinct
3
Q
normalized
A
entities with repeating groups
4
Q
domain
A
attribute values: date, number, text
5
Q
representation
A
employee(no, surname, dept)
6
Q
relational algebra
A
selection projection cartesian product union intersection set difference
7
Q
selection
A
rows
8
Q
projection
A
columns
9
Q
union
A
select all
10
Q
intersection
A
giao nhau
11
Q
difference 0 minus
A
k giao nhau
12
Q
cartesian product
A
contatenate
