On 12-07-16 06:57 PM, Rick James wrote:
Plan A: Would the anti-UNION problem be solved by hiding the UNION in a subquery? The outer query would simply return what the UNION found.
Of course! Yes, problem solved.
Plan B: Insert every row twice into expression_expression -- (e1,e2) and also (e2,e1). Then, you need only one index into that table, and you don't need to UNION (or the LEFT JOINs).
This is the approach that I was considering for when the app is rewritten. (I've inherited a disaster.)
Thank again for the tip. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
