无论环境如何,以下查询都需要超过30秒的时间来计算.
SELECT COUNT( r.response_answer )
FROM response r
INNER JOIN (
SELECT G.question_id
FROM question G
INNER JOIN answer_group AG ON G.answer_group_id = AG.answer_group_id
WHERE AG.answer_group_stat = 'statistic'
) AS q ON r.question_id = q.question_id
INNER JOIN org_survey os ON os.org_survey_code = r.org_survey_code
WHERE os.survey_id =42
AND r.response_answer = 5
AND DATEDIFF( NOW( ) , r.added_dt ) <1000000
AND r.uuid IS NOT NULL
当我解释查询时,
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL …