Re: pg_generate_sequence and info_schema patch (Was: SELECT

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Joe Conway wrote:
| Tom Lane wrote:
|
|> Maybe the best documentation answer is to create a new subsection in the
|> Functions chapter. This may be our first standard set-returning
|> function but I bet it will not be the last, so the shortness of the
|> subsection doesn't bother me.
|
|
| A first shot at documentation for generate_series() is available here in
| html form:
| http://www.joeconway.com/functions-srf.html

I seen there:

select * from generate_series(5,1,-2);
~ generate_series
- -----------------
~ 5
~ 3
~ 1
(3 rows)

I understood on your past posts that instead this result
was obtained with:

select * from generate_series(5,1,2);
~ generate_series
- -----------------
~ 5
~ 3
~ 1
(3 rows)

I think that is better have:
~ if start < end the series is ascending
~ if start > end the series is descending

~ if step > 0 the series is ascending
~ if step < 0 the series is descending
~ ( step can not be 0 )

if ( start < end ) and ( step < 0 ) the result set is empty
if ( start > end ) and ( step > 0 ) the result set is empty

IMHO this is the more natural behavior.

my 2 cents.

Regards
Gaetano Mendola

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