generate_series function in Amazon Redshift

Question

I tried the below:

SELECT * FROM generate_series(2,4);
generate_series
-----------------
           2
           3
           4
(3 rows)

SELECT * FROM generate_series(5,1,-2);                                                             
generate_series
-----------------
           5
           3
           1
(3 rows)

But when I try,

select * from generate_series('2011-12-31'::timestamp, '2012-12-31'::timestamp, '1 day');

It generated error.

ERROR:  function generate_series(timestamp without time zone, timestamp without time zone, "unknown") does not exist
HINT:  No function matches the given name and argument types. You may need to add explicit type casts.

I use PostgreSQL 8.0.2 on Redshift 1.0.757.
Any idea why it happens?

UPDATE:

generate_series is working with Redshift now.

SELECT CURRENT_DATE::TIMESTAMP  - (i * interval '1 day') as date_datetime 
FROM generate_series(1,31) i 
ORDER BY 1

This will generate last 30 days date

Answer 1

The version of generate_series() that supports dates and timestamps was added in Postgres 8.4.

As Redshift is based on Postgres 8.0, you need to use a different way:

select timestamp '2011-12-31 00:00:00' + (i * interval '1 day')
from  generate_series(1, (date '2012-12-31' - date '2011-12-31')) i;

If you "only" need dates, this can be abbreviated to:

select date '2011-12-31' + i
from  generate_series(1, (date '2012-12-31' - date '2011-12-31')) i;