Numeric Overflow in Recursive Query : Teradata - sql

Question

I'm new to teradata. I want to insert numbers 1 to 1000 into the table test_seq, which is created as below.
create table test_seq(
seq_id integer
);
After searching on this site, I came up with recusrive query to insert the numbers.
insert into test_seq(seq_id)
with recursive cte(id) as (
select 1 from test_dual
union all
select id + 1 from cte
where id + 1 <= 1000
)
select id from cte;
test_dual is created as follows and it contains just a single value. (something like DUAL in Oracle)
create table test_dual(
test_dummy varchar(1)
);
insert into test_dual values ('X');
But, when I run the insert statement, I get the error, Failure 2616 Numeric overflow occurred during computation.
What did I do wrong here? Isn't the integer datatype enough to hold numeric value 1000?
Also, is there a way to write the query so that i can do away with test_dual table?

Answer 1

When you simply write 1 the parser assigns the best matching datatype to it, which is a BYTEINT. The valid range of values for BYTEINT is -128 to 127, so just add a typecast to INT :-)
Usually you don't need a dummy DUAL table in Teradata, "SELECT 1;" is valid, but in some cases the parser still insists on a FROM (don't ask me why). This trick should work:
SEL * FROM (SELECT 1 AS x) AS dt;
You can create a view on this:
REPLACE VIEW oDUAL AS SELECT * FROM (SELECT 'X' AS dummy) AS dt;
Explain "SELECT 1 FROM oDUAL;" is a bit stupid, so a real table might be better. But to get efficient access (= single AMP/single row) it must be defined as follows:
CREATE TABLE dual_tbl(
dummy VARCHAR(1) CHECK ( dummy = 'X')
) UNIQUE PRIMARY INDEX(dummy); -- i remember having fun when you inserted another row in Oracle's DUAL :_)
INSERT INTO dual_tbl VALUES ('X');
REPLACE VIEW oDUAL AS SELECT dummy FROM dual_tbl WHERE dummy = 'X';
insert into test_seq(seq_id)
with recursive cte(id) as (
select cast(1 as int) from oDUAL
union all
select id + 1 from cte
where id + 1 <= 1000
)
select id from cte;
But recursion is not an appropriate way to get a range of numbers as it's sequential and always an "all-AMP step" even if it the data resides on a single AMP like in this case.
If it's less than 73414 values (201 years) better use sys_calendar.calendar (or any other table with a known sequence of numbers) :
SELECT day_of_calendar
FROM sys_calendar.CALENDAR
WHERE day_of_calendar BETWEEN 1 AND 1000;
Otherwise use CROSS joins, e.g. to get numbers from 1 to 1,000,000:
WITH cte (i) AS
( SELECT day_of_calendar
FROM sys_calendar.CALENDAR
WHERE day_of_calendar BETWEEN 1 AND 1000
)
SELECT
(t2.i - 1) * 1000 + t1.i
FROM cte AS t1 CROSS JOIN cte AS t2;