How different is WHERE id IN(4) versus WHERE id = 4?

Question

Possible Duplicate:
Why would an IN condition be slower than “=” in sql?

Is there any performance difference between doing:

SELECT foo FROM bar WHERE id IN (4)

Versus

SELECT foo FROM bar WHERE id = 4

That question is talking about using an IN statment in a subquery, e.g `SELECT FROM foo WHERE id IN (SELECT..)` whereas my question is the diff. between `SELECT WHERE id IN (val)` vs `SELECT WHERE id = val`. Hence its not a duplicate. — Ali, Aug 22 '12 at 20:30

score 0 · Answer 1 · answered Aug 22 '12 at 20:19

0

I believe the MySQL optimizer will convert the id IN(4) to id = 4, so no performance difference

answered Aug 22 '12 at 20:19

user387049

1

does it say so anywhere in the manual? – Ali Aug 22 '12 at 20:25
2

Do you know or do you just think so? Please dont answer questions with "I believe so" please supply proof – bretterer Aug 22 '12 at 20:38

1 Answers1