我有这个Hive查询,不断向我显示此错误:
Warning: Map Join MAPJOIN[61][bigTable=?] in task 'Map 3' is a cross product
Warning: Map Join MAPJOIN[58][bigTable=xxx_table] in task 'Map 3' is a cross product
这是一个交叉产品。我必须避免这种情况,因为查询需要太长时间,太多内存
这是查询:
WITH view1 AS
(
SELECT Max(date) AS max_date
FROM table1 )
view2 as (
SELECT * FROM table
)
SELECT
*
FROM view1,view2
WHERE
view2.date > view1.max_date
您是否有解决此警告的想法? 我也尝试了EXPLAIN查询,但我听不懂日志