Gbase8s 查询条件优化(3)

MAX OVER函数的改写

示例1：

SELECTMIN(kpi_value) OVER (PARTITION BY a.kpi_id,a.brand_id,a.city_id ORDERBY FLOOR( DAYS(a.kpi_date) ) RANGE BETWEEN 1 preceding AND 1preceding ) as last_valueFROM a;

改写为：

SELECT(SELECT MIN(kpi_value) FROM kpi_values aa WHERE aa.kpi_id = a.kpi_idAND aa.brand_id = a.brand_id AND aa.city_id = a.city_id AND aa.kpi_date =DATE_SUB(a.kpi_date, INTERVAL 1 DAY)) as last_value FROM a ORDER BYa.kpi_id,a.brand_id,a.city_id,a.kpi_date;