Re: Should "select 'nan'::float = 'nan'::float; " return false as per IEEE 754

Would this introduce problems finding rows where the stored value is NaN? You'd need to add a function or operator to avoid that.

Il giorno 28/ott/2012, alle ore 20:43, Hannu Krosing ha scritto:

> This is how PostgreSQL currently works -
>
> test=# select 'NaN'::float = 'NaN'::float as must_be_false;
> must_be_false
> ----------
> t
> (1 row)
>
> I think that PostgreSQL's behaviour of comparing two
> NaN-s as equal is wrong and Iwe should follow the IEEE 754 spec here
>
> As per IEEE 754 a NaN behaves similar to NULL in SQL.
>
> There is some discussion of why it is so at:
>
> http://stackoverflow.com/questions/1565164/what-is-the-rationale-for-all-comparisons-returning-false-for-ieee754-nan-values
>
> especially the first comment
>
> ---------
> Hannu
>
>
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