优化语句select collectite0_.ID as ID48_, collectite0_.COLLECT_TIME as COLLECT2_48_, collectite0_.COLLECT_TYPE as COLLECT3_48_, collectite0_.COLLECT_VALUE as COLLECT4_48_, collectite0_.DATA_EXTRACTION_TYPE as DATA5_48_, collectite0_.HOST_ID as HOST6_48_ from G2_T_COLLECT_ITEM collectite0_ where collectite0_.COLLECT_TYPE='memory' and collectite0_.HOST_ID='ff808081632a5fb8016347f5fa4f7c4a' order by collectite0_.COLLECT_TIME desc limit 5;

这条 SQL 语句可以进行如下优化：

1. 创建索引：在 `G2_T_COLLECT_ITEM` 表上创建一个联合索引，包含 `COLLECT_TYPE` 和 `HOST_ID` 字段，可以加速筛选条件中的两个字段。

2. 精简查询字段：只查询需要的字段，避免查询不必要的字段，可以减少查询时间和网络带宽的消耗。

最终优化后的 SQL 语句如下：

SELECT collectite0_.ID, collectite0_.COLLECT_TIME, collectite0_.COLLECT_VALUE
FROM G2_T_COLLECT_ITEM collectite0_
WHERE collectite0_.COLLECT_TYPE='memory' AND collectite0_.HOST_ID='ff808081632a5fb8016347f5fa4f7c4a'
ORDER BY collectite0_.COLLECT_TIME DESC
LIMIT 5;

希望对你有所帮助！

相关问题

select COLLECT_TIME, PERF_VALUE, t1.unit, RULEA, RULEB, RULEC from ( select COLLECT_TIME, PERF_VALUE, UNIT as unit, EQP_OBJ_ID, OBJECT_TYPE, INDEX_TYPE, DEVICE_ID, INDEX_NAME from t_perf_sensor_history tpsh, t_perf_defined tpd where PERF_OBJ_ID = tpd.OBJ_ID ) as t1 left join t_alarm_rule tar on IF(tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID, tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID, tar.ALARM_OBJECT_TYPE = OBJECT_TYPE) where 1=1 and COLLECT_TIME BETWEEN DATE_SUB(NOW(), INTERVAL 53 DAY) AND NOW() union select COLLECT_TIME, PERF_VALUE, t1.unit, RULEA, RULEB, RULEC from ( select COLLECT_TIME, PERF_VALUE, UNIT as unit, EQP_OBJ_ID, OBJECT_TYPE, INDEX_TYPE, DEVICE_ID, INDEX_NAME from t_perf_sensor_run tpsr, t_perf_defined tpd where PERF_OBJ_ID = tpd.OBJ_ID ) as t1 left join t_alarm_rule tar on IF(tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID, tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID, tar.ALARM_OBJECT_TYPE = OBJECT_TYPE) where 1=1 and COLLECT_TIME BETWEEN DATE_SUB(NOW(), INTERVAL 53 DAY) AND NOW() order by COLLECT_TIME desc怎么优化速度

首先，可以优化查询语句中的子查询，将其转换为 JOIN。例如：

SELECT COLLECT_TIME, PERF_VALUE, tpd.UNIT AS unit, t1.EQP_OBJ_ID, t1.OBJECT_TYPE, t1.INDEX_TYPE, t1.DEVICE_ID, t1.INDEX_NAME, tar.RULEA, tar.RULEB, tar.RULEC 
FROM ( 
    SELECT tpsh.COLLECT_TIME, tpsh.PERF_VALUE, tpsh.EQP_OBJ_ID, tpsh.OBJECT_TYPE, tpsh.INDEX_TYPE, tpsh.DEVICE_ID, tpsh.INDEX_NAME 
    FROM t_perf_sensor_history tpsh 
    JOIN t_perf_defined tpd ON tpsh.PERF_OBJ_ID = tpd.OBJ_ID 
    WHERE tpsh.COLLECT_TIME BETWEEN DATE_SUB(NOW(), INTERVAL 53 DAY) AND NOW() 
    
    UNION ALL 
    
    SELECT tpsr.COLLECT_TIME, tpsr.PERF_VALUE, tpsr.EQP_OBJ_ID, tpsr.OBJECT_TYPE, tpsr.INDEX_TYPE, tpsr.DEVICE_ID, tpsr.INDEX_NAME 
    FROM t_perf_sensor_run tpsr 
    JOIN t_perf_defined tpd ON tpsr.PERF_OBJ_ID = tpd.OBJ_ID 
    WHERE tpsr.COLLECT_TIME BETWEEN DATE_SUB(NOW(), INTERVAL 53 DAY) AND NOW() 
) t1 
LEFT JOIN t_alarm_rule tar ON (tar.ALARM_OBJECT_TYPE = t1.DEVICE_ID OR tar.ALARM_OBJECT_TYPE = t1.OBJECT_TYPE) 
ORDER BY COLLECT_TIME DESC

这样可以避免重复子查询的问题，提高查询效率。

其次，可以考虑对表进行索引优化。在这个查询中，可以为 t_perf_sensor_history 表的 COLLECT_TIME 字段和 PERF_OBJ_ID 字段，以及 t_perf_sensor_run 表的 COLLECT_TIME 字段和 PERF_OBJ_ID 字段建立联合索引，以优化子查询的效率。

最后，可以考虑对 WHERE 子句中的日期范围限制进行优化。例如，可以根据业务需求调整日期范围的大小，避免查询过多无用数据。同时，可以考虑将日期范围限制转换为日期时间戳的形式，以避免对日期字符串的转换和比较，提高查询效率。

优化SQL语句SELECT * FROM ( SELECT d.driver_id, d.driver_name, v.numberplate, v.vehicle_type, d.driver_photo, d.phone_number, ( SELECT count( 1 ) FROM waybill_info WHERE transport_status<>9 and driver_id = d.driver_id ) AS transportStatus FROM driver_info AS d INNER JOIN driver_vehicle_bind AS d1 ON d.driver_id = d1.driver_id INNER JOIN vehicle_info AS v ON d1.vehicle_id = v.vehicle_id WHERE d1.is_use = 1 AND d1.bind_status = 1 AND v.cert_status = 1 AND d.cert_status = 2 ) AS s WHERE s.driver_id NOT IN ( SELECT driver_id FROM collect_blacklist WHERE user_id = #{userId})

可以尝试对该SQL语句进行以下优化：

1. 减少不必要的列查询：在SELECT语句中只选择需要的列，而不是使用通配符*，可以减少数据传输量，提高查询效率。

2. 使用JOIN代替子查询：在内部查询中使用JOIN语句代替子查询，可以提高查询效率。因为JOIN语句可以将多个表的数据一次性查询出来，而子查询会多次查询。

3. 使用EXISTS代替IN：在外部查询中使用EXISTS代替IN，可以提高查询效率。因为EXISTS只需要判断是否存在符合条件的记录，而IN需要先查询出符合条件的所有记录。

下面是优化后的SQL语句：

SELECT d.driver_id, d.driver_name, v.numberplate, v.vehicle_type, d.driver_photo, d.phone_number, count(w.waybill_id) AS transportStatus
FROM driver_info d
INNER JOIN driver_vehicle_bind d1 ON d.driver_id = d1.driver_id
INNER JOIN vehicle_info v ON d1.vehicle_id = v.vehicle_id
LEFT JOIN waybill_info w ON w.driver_id = d.driver_id AND w.transport_status <> 9
WHERE d1.is_use = 1
AND d1.bind_status = 1
AND v.cert_status = 1
AND d.cert_status = 2
AND NOT EXISTS (
SELECT 1
FROM collect_blacklist
WHERE driver_id = d.driver_id
AND user_id = #{userId}
)
GROUP BY d.driver_id, d.driver_name, v.numberplate, v.vehicle_type, d.driver_photo, d.phone_number
ORDER BY d.driver_id;

注意，优化SQL时需要根据具体情况进行选择和应用，以上仅供参考。