为什么解释分区显示每个选择查询的第一个分区？

Question

我在mysql 5.1.6 *版本上有一个名为edr的表。我使用alter -

对表进行了分区

ALTER TABLE edr PARTITION BY RANGE (TO_DAYS(eventDate))
 (
   PARTITION apr25 VALUES LESS THAN (TO_DAYS('2014-04-26')),
   PARTITION apr26_30 VALUES LESS THAN (TO_DAYS('2014-05-01')),
   PARTITION may01_05 VALUES LESS THAN (TO_DAYS('2014-05-06')),
   PARTITION may06_10 VALUES LESS THAN (TO_DAYS('2014-05-11')),
   PARTITION may11_15 VALUES LESS THAN (TO_DAYS('2014-05-16')),
   PARTITION may16_20 VALUES LESS THAN (TO_DAYS('2014-05-21')),
   PARTITION may21_25 VALUES LESS THAN (TO_DAYS('2014-05-26')),
   PARTITION may26_31 VALUES LESS THAN (TO_DAYS('2014-06-01')),
   PARTITION june01_05 VALUES LESS THAN (TO_DAYS('2014-06-06')),
   PARTITION june06_10 VALUES LESS THAN (TO_DAYS('2014-06-11')),
   PARTITION june11_15 VALUES LESS THAN (TO_DAYS('2014-06-16')));

现在当我运行任何查询时，例如：

explain partitions select count(*) from edr where eventdate > '2014-05-21';

它为分区输出 - apr25，may21_25，may26_31，jun01_05，jun_06_10，jun11_15。 在分区apr25中没有这种条件的记录。

请告诉我上述查询或分区问题是否有任何问题。

Answer 1

这是MySQL错误：explained here。 尝试创建包含小于（0）

的值的第一个分区

  

PARTITION unused价值低于（0）;