Re: bug or feature, || -operator and NULLs

> The following query returns NULL in PG:
> SELECT NULL || 'fisk';
> 
> But in Oracle, it returns 'fisk':
> SELECT NULL || 'fisk' FROM DUAL;
> 
> The latter seems more logical...

Why would it be more logical ?

NULL means "value not known".

Concatenate "value not known" with 'fisk' -> what's the logical answer?

I would say the logical result is 'value not known'... if one of the
components is not known, how can you know what is the result ?

Cheers,
Csaba.