> 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.
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
