Question

I have a large table containing some 15 million row, all varchar data. I ran a self join query on it which has a 3 self table join, something like this:

SELECT sj1.uid FROM tbl sj1 
JOIN tbl sj2 ON sj1.uid = sj2.uid 
JOIN tbl sj3 ON sj1.uid = sj3.uid
WHERE sj1.product_code = 'tb'
AND sj2.product_code = 'im'
AND sj3.product_code = 'mg'

Now it’s been over 2 hours and when I check show full processlist I get status sending data and nothing else. I would like to know if there’s any way to know how many rows have been processed by this query or any other relevant status. I can’t even kill this query with a doubt that it might be nearing its end and if interrupted it will be a big waste of resource. Any help with this?

This is the what EXPLAIN explained me:

+----+-------------+-------+------+-------------------+-------------------+---------+----------------------------------------+----------+-------------+
| id | select_type | table | type | possible_keys     | key               | key_len | ref                                    | rows     | Extra       |
+----+-------------+-------+------+-------------------+-------------------+---------+----------------------------------------+----------+-------------+
|  1 | SIMPLE      | a     | ALL  | ix_unique_user_id | NULL              | NULL    | NULL                                   | 14251264 | Using where |
|  1 | SIMPLE      | b     | ref  | ix_unique_user_id | ix_unique_user_id | 103     | ph_usertrack_analysis.a.unique_user_id |        2 | Using where |
|  1 | SIMPLE      | c     | ref  | ix_unique_user_id | ix_unique_user_id | 103     | ph_usertrack_analysis.a.unique_user_id |        2 | Using where |
+----+-------------+-------+------+-------------------+-------------------+---------+----------------------------------------+----------+-------------+

So index on unique_user_id is being used

Answer 1

No, you cannot get any information on query progress out of MySQL.