⋈
Symbol  Format  Data 

⋈  Code Point 
U+22C8 
TeX 
\bowtie 

SVG 
The ‘⋈’ (bow tie) symbol is used in relational algebra to denote the natural join of two relations.
For example, if we have two relations R and S:
This denotes the natural join of R and S, i.e., the set of all combinations of tuples in R and S that are equal on their common attribute names.