# Relational Operator - Join

join is a relational operator that pair tuples (row) of two relations (table, …) according to a condition (predicate).

## Notation

### Relational

$$\LARGE R_1 \bowtie_c R_2$$ where:

### Symbol

Type Symbol Unicode Point Latex
Join $\Join$ 2A1D \Join
Left Outer Join 27D5 \leftouterjoin
Right Outer Join 27D6 \rightouterjoin
Full Outer Join 27D7 \fullouterjoin

## Rule

$$\LARGE R_1 \bowtie_{ predicate } R_2 = \sigma_{ predicate } ( R_1 \times R_2 )$$ which means:

is the same than

## Type

Short hand:

### Implementation

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