HP Vertica: partition by TIMESTAMPTZ field

Question

I'm trying to re-partition some table using week number counting from some day:

my_fact table contains a field called time_stamp of type TIMESTAMPTZ

Unfortunately, re-partition doesn't work, and I'm getting the error:

MyDB=> ALTER TABLE my_fact PARTITION BY MOD(TIMESTAMPDIFF('day', time_stamp::TIMESTAMP, TIMESTAMP '2013-09-23'), 156) REORGANIZE;

NOTICE 4954:  The new partitioning scheme will produce 12 partitions
ROLLBACK 2552:  Cannot use meta function or non-deterministic function in PARTITION BY expression

Should the cast of time_stamp to TIMESTAMP strip any time zone related info from this field thus making it deterministic?

Thanks!

Answer 1

Since I got no answer, I'm writing here what I've ended up with:

ALTER TABLE my_fact PARTITION BY 
  MOD(
     TIMESTAMPDIFF(
        'day',
        '2013-09-23'::timestamptz AT TIME ZONE 'UTC',
        time_stamp AT TIME ZONE 'UTC'),
     156)
REORGANIZE;

This solution works.

Answer 2

Take a look at the date_part() function, you can use the TIMESTAMPTZ as its source column: Example :

**The number of the week of the calendar year that the day is in.**

SELECT EXTRACT(WEEK FROM TIMESTAMP '2001-02-16 20:38:40');
Result: 7
SELECT EXTRACT(WEEK FROM DATE '2001-02-16');
Result: 7