Weird: explain partitions says a single row belong to two partitions...

[Christian Cunlif]

Hi,

I have a table partitioned with an int column ID.
I run the query:
explain partitions select ID, date from mypurchase where ID = 37

and it returns (in the partition column):
d_21, d_23
which corresponds to 2 partitions!!?

If I run a "SELECT partition_name, partition_description FROM information_schema.PARTITIONS WHERE ...", I get:
name description
d_20 35
d_21 37
d_23 39


So why does "explain partitions" return 2 partition for a single record? A bug?

Thanks for your help
Chris