Re: Feature request: Improve allowed values for generate series - Mailing list pgsql-hackers

From Pavel Stehule
Subject Re: Feature request: Improve allowed values for generate series
Date
Msg-id CAFj8pRAhiyMAKEsESkntL7bhvM-FXUp0u58BOKrQ8nGqm6=P5A@mail.gmail.com
Whole thread Raw
In response to Feature request: Improve allowed values for generate series  (Eugen Konkov <kes-kes@yandex.ru>)
List pgsql-hackers


st 11. 11. 2020 v 19:59 odesílatel Eugen Konkov <kes-kes@yandex.ru> napsal:
Hello Pgsql-hackers,

Seems I fall into corner case:

test=> SELECT * FROM generate_series( '2020-11-09', '2020-11-09', INTERVAL '00:00:00' );
ERROR:  step size cannot equal zero

But:
test=> SELECT * FROM generate_series( '2020-11-09', '2020-11-10', INTERVAL '1 day' );
    generate_series     
------------------------
 2020-11-09 00:00:00+02
 2020-11-10 00:00:00+02
(2 rows)

Here  we  start  at  2020-11-09, add interval of one day and finish at 2020-11-10
Done! series is generated.

In  first  case  I  expect that I start at 2020-11-09, add interval of zero and finish at 2020-11-09
Everything is consistent.

test=> SELECT * FROM generate_series( '2020-11-09', '2020-11-09', INTERVAL '00:00:00' );
    generate_series
------------------------
 2020-11-09 00:00:00+02
(1 row)


So   I   feature  request  to  allow  zero size step for cases when  start point is equest to finish

What do you think?

What is the real use case?  Current implementation is very simple - increment should not be zero, and then we know so there is no infinity cycle.

Regards

Pavel





--
Best regards,
Eugen Konkov



pgsql-hackers by date:

Previous
From: Eugen Konkov
Date:
Subject: Re: Feature request: Improve allowed values for generate series
Next
From: "David G. Johnston"
Date:
Subject: Re: Feature request: Improve allowed values for generate series