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  • Gloria Segundo thinks this is interesting:

A better use for EXISTS is typically to validate the calling query against the results of a subquery. The following query finds all movies with no recognition:

SELECT M.TITLE FROM MOVIE M WHERE NOT EXISTS
 (SELECT MOVIE_ID FROM RECOGNITION WHERE MOVIE_ID = M.MOVIE_ID);

An equivalent query using IN would be as follows:

SELECT TITLE FROM MOVIE WHERE MOVIE_ID NOT IN
 (SELECT MOVIE_ID FROM RECOGNITION);

From

Cover of Oracle® 9i SQL Exam Cram™ 2 (Exam 1Z0-007)

Note

pendiente no le entiendo si el RECOGNITION es tabla o algo