Feature request: Improve allowed values for generate series

[Eugen Konkov]

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?


-- 
Best regards,
Eugen Konkov