数据库:zhcxkj_center_strategy_comprehensive
查询时间:284.806
执行次数: 30
扫描行数:3245.17
发送行数:1
指纹SQL: SELECT MAX ( id ) as max_id FROM ( SELECT id FROM ? WHERE create_time < ? AND id > ? ORDER BY id LIMIT ? ) AS batch ;
真实SQL:SELECT MAX(id) as max_id FROM ( SELECT id FROM t_promotion_candidate_detail_mercadolibre_1 WHERE create_time < 2025-10-08 04:03:21 AND id > 0 ORDER BY id LIMIT 10000 ) AS batch;
无人工修改
AISQL修改建议:SELECT MAX(id) AS max_id
FROM t_promotion_candidate_detail_mercadolibre_1
WHERE create_time < 2025-10-08 04:03:21
AND id > 0
AND id >= (SELECT id
FROM t_promotion_candidate_detail_mercadolibre_1
WHERE create_time < 2025-10-08 04:03:21
AND id > 0
ORDER BY id
LIMIT 1 OFFSET 9999)
explain表:
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | filtered | Extra |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | PRIMARY | <derived2> | None | ALL | None | None | None | None | 10000 | 100 | None |
| 2 | DERIVED | t_promotion_candidate_detail_mercadolibre_1 | None | range | PRIMARY | PRIMARY | 8 | None | 4801300 | 33.33 | Using where |
额外建议:
索引建议:
建议添加索引:ALTER TABLE t_promotion_candidate_detail_mercadolibre_1 ADD INDEX idx_create_time_id(create_time,id);
【t_promotion_candidate_detail_mercadolibre_1】表 【create_time,id】字段,索引分析:
+--------------------------------+--------------+---------------+---------------+
| TABLE_NAME | INDEX_NAME | COLUMN_NAME | CARDINALITY |
+================================+==============+===============+===============+
| t_promotion_candidate_detail_m | PRIMARY | id | 9274188 |
| ercadolibre_1 | | | |
+--------------------------------+--------------+---------------+---------------+
@王金锋 把这个优化SQL的图 附上 性能bug 点解决