Question

I have this users table with:

id : int (255)
name: char (100)
last_comment_target: int(100)
last_comment_date: datetime

This table has around 1.3mil rows.

PKEY and BTREE is on id, last_comment_target, and last_comment_date.

And, I am trying to perform a range query:

SELECT * FROM users 
WHERE id IN (1,2,3,5,...[around 5000 ids]) 
AND last_comment_target > 0 
ORDER BY last_comment_dt DESC LIMIT 0,20;

Sometimes the query can take as long as 3 seconds. I wonder if there are better ways to optimize this query. Or, if this query can be rewritten.

Thank you so much for your help.

Answer 1

SELECT u.* 
FROM 
    users u
    JOIN (
        SELECT 1 id 
        UNION ALL
        SELECT 2 id
        UNION ALL
        :
        :
        SELECT 5000 id
    ) ids ON ids.id = u.id
WHERE 
    last_comment_target > 0 
ORDER BY 
    last_comment_dt DESC 
LIMIT 0, 20;