Hi All!

Why is too much difference in time execution between these two queries:

SELECT rc.id AS id, rc.name
FROM realisation_category rc
WHERE EXISTS (
SELECT * FROM realisation r, post p WHERE (r.realisation_category_id = rc.id AND r.site_id = 1)
OR (p.realisation_category_id = rc.id AND p.site_id = 1)
)
[2016-06-03 01:23:12] 35 row(s) retrieved starting from 1 in 14s 591ms (14s 612ms total)

SELECT rc.id AS id, rc.name
FROM realisation_category rc
WHERE EXISTS (
SELECT * FROM realisation r WHERE r.realisation_category_id = rc.id AND r.site_id = 1
) OR EXISTS (
SELECT * FROM post p WHERE p.realisation_category_id = rc.id AND p.site_id = 1
)
[2016-06-03 01:25:25] 35 row(s) retrieved starting from 1 in 64ms (86ms total)

Thanks