Does the order of the columns in a SELECT statement make a difference?
- by Frank Computer
This question was inspired by a previous question posted on SO, "Does the order of the WHERE clause make a differnece?". Would it improve a SELECT statement's performance if the the columns used in the WHERE section are placed at the begining of the SELECT statement?
example:
SELECT customer.id,
transaction.id,
transaction.efective_date,
transaction.a,
[...]
FROM customer, transaction
WHERE customer.id = transaction.id;
I do know that limiting the list of columns to only the needed ones in a SELECT statement improves performance as opposed to using SELECT * because the current list is smaller.
