1. Chapter 4 Relational Algebra
Relational Languages
Relational Algebra

2. Relational Languages Procedural language Non-procedural language
Relational algebra
Non-procedural language
Relational Calculus (pp )

3. Relational Algebra Intra Relation
Selection - horizontal partition
SELECT relation WHERE condition [GIVING relation]
 condition(relation)
Projection - vertical partition
PROJECT relation OVER (attribute, attribute,...)[GIVING relation]
 attributes(relation)

4. Union-Compatible
Union - tuples in either of 2 union compatible relations
relation1 UNION relation2 [GIVING relation]
relation1  relation2
Difference - tuples in one union compatible relation, but not other
relation1 MINUS relation2 [GIVING relation]
relation1 - relation2

5. Union-Compatible
Intersection - tuples in both of 2 union compatible relations
relation1 INTERSECT relation2 [GIVING relation]
relation1  relation2

6. Any 2 Relations Product - Cartesian product of any two relations
relation1 TIMES relation2 [GIVING relation]
relation1 relation2
Join - common domain
relation1 JOIN relation2 WHERE condition [GIVING relation]
relation1conditionrelation2
Division
relation1 divided by relation2 [GIVING relation]
relation1 / relation2

7. Types of Join
Equi : based on equality with 2 identical attribute columns
Theta : a join based on a relational operator (=,<,>,<=,>=,~=)
Natural : equijoin with no duplicate column
Outer : includes tuples without matches (left, right, full)

8. Types of Join Semi-join Semi-theta-join Semi-natural join
relation1 SEMIJOIN relation2 WHERE condition [GIVING relation]
relation1 lxcondition relation2
Semi-theta-join
Semi-natural join

9. Assignment Review chapters 1-4 Read Chapters 6-5 Do Exercise 4.12
Due date: