mysql解釋時間

Question

我正在做以下選擇查詢的解釋計劃，解釋計劃永遠不會返回。解釋計劃在2-3分鐘之前回來，但現在它永遠不會回來。以下是我正在運行的解釋查詢

explain SELECT * FROM 
((
SELECT DISTINCT hi.target_profile_id, hi.handset_id 
FROM handset_inclusions hi, 
campaigns c, 
campaigns_target_profiles ctp 
WHERE hi.target_profile_id = ctp.target_profile_id 
AND c.id=ctp.campaign_id 
AND c.active=1 
AND c.house_ad = true 
ORDER BY target_profile_id, handset_id) 
UNION DISTINCT 
(
SELECT DISTINCT hi.target_profile_id, hi.handset_id 
FROM handset_inclusions hi, 
campaigns c, 
campaign_flights f, 
campaigns_target_profiles ctp 
WHERE hi.target_profile_id = ctp.target_profile_id 
AND c.id=ctp.campaign_id 
AND c.active=1 
AND c.house_ad = false 
AND c.id = f.campaign_id 
AND (f.active_flight = true or c.id in (199,857,947) 
     OR (NOW() >= DATE_SUB(f.start_time, INTERVAL 6 HOUR) 
      AND NOW() <= DATE_ADD(f.end_time, INTERVAL 6 HOUR))) 
ORDER BY target_profile_id, handset_id) 
UNION DISTINCT 
(SELECT prof.target_profile_id, h.id as handset_id 
FROM (SELECT distinct (pc.target_profile_id) as target_profile_id 
     FROM placements p, sites s, publishers pubs, placement_3PNchannel pc 
     LEFT OUTER JOIN 3PNchannel c 
     ON c.id = pc.3PNchannel_id 
     WHERE p.id = pc.placement_id 
     AND p.siteid = s.id 
     AND pubs.id = s.publisherid 
     AND pc.active = TRUE 
     AND pubs.allows_3pn)prof, handsets h, handset_inclusions i 
WHERE prof.target_profile_id = i.target_profile_id 
    AND i.handset_id = h.id)) t 
    order by t.target_profile_id; 

Answer 1

這是一個bug。 MySQL似乎在運行EXPLAIN時執行了子查詢。

它似乎應該修復在MySQL> = 5.6