Cross joins can be created by having tables and joins separated by a comma.
SELECT *
FROM a,b,c
You may be able to speed up cross join queries by moving related parts of the where clause into B,C as sub-queries in this case.
Example
SELECT *
FROM a,b, (SELECT value1, value2 FROM c) AS cx
WHERE a.id = b.id AND b.value = cx.value1
Comments
Please sign in to leave a comment.