Accessing more partitions than needed

[dileep ch]

Hi,

I have column with date field and i partitioned using to_days function

PARTITION BY RANGE (to_days(cdate))
(PARTITION p0 VALUES LESS THAN (734928) ENGINE = InnoDB,
PARTITION p1 VALUES LESS THAN (734943) ENGINE = InnoDB,
PARTITION p2 VALUES LESS THAN (734959) ENGINE = InnoDB,
PARTITION p3 VALUES LESS THAN (734974) ENGINE = InnoDB
.....

Partition p0 means values less than '2012-03-01'
p1 less than '2012-03-16'
p2 less than '2012-04-01'
p3 less than '2012-04-16'
......

So when i'm select cdate between '2012-03-01' and '2012-03-31'

It was accessing p0,p1,p2
But i think it shouls access only p1 and p2 according partition purning.

And also accessing p0 when cdate>'2012-03-31'

What is the problem with this.

And can i partition in any other way with date column.