, , .
- (UNION) , , -.
- (INTERSECT) , , -.
- , (MINUS) , , - , , , .
- (TIMES) , , , .
- (WHERE) , -, .
- (PROJECT) , -.
- (JOIN) , .
- (DIVIDE BY) . , , ( ) .
- (RENAME) , , .
- (:=) .
( , ) , , - . , . :
RENAME WHERE = PROJECT TIMES = JOIN = INTERSECT = DIVIDE BY UNION = MINUS
. 4.1. .
. 3.1.