Re: plpgsql FOR loop doesn't guard against strange step values - Mailing list pgsql-hackers

Tom Lane wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
>   
>> I suspect we have a significant incompatibility with PLSQL in this area. 
>>     
>
> Ugh.  Google seems to confirm your thought that Oracle expects
>
>   
>>   FOR i IN REVERSE 1..10 LOOP
>>     
>
> which is not the way we are doing it.  Not sure if it's worth trying to
> fix this --- the conversion pain would be significant.  I agree we gotta
> document it, however; will go do so.
>
> Note that in the Oracle worldview it still wouldn't be sensible to use
> a negative step.
>
>
>   

Quite so. I think we should probably require the step to be greater than 
0, whether or not we are using REVERSE, and choose to use it as an 
increment or decrement as appropriate.

cheers

andrew