Identify a virtual partition

A virtual partition is identified by a calendar index or a time stamp.

The calendar index is a positive integer value, where 0 is the first virtual partition. For example, for the 2010monthly calendar used in the example, the calendar index 0 identifies the virtual partition for January 2010, and the calendar index 1 identifies February 2010.

When using a time stamp, the time stamp value is internally mapped into a calendar index. For the 2010monthly calendar used in the example, all time stamps between '2010-01-01 00:00:00.00000'::datetime year to fraction(5)', including this value, and '2010-02-01 00:00:00.00000'::datetime year to fraction(5)', excluding this value, identify the virtual partition for January 2010.

The time stamp is automatically extended to 'datetime year to fraction(5)'. For example, '2010-01'::datetime year to month' is equivalent to '2010-01-01 00:00:00.00000'::datetime year to fraction(5)'.