Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
>
>> On 06/16/2009 04:32 PM, Robert Haas wrote:
>>
>>> Note that even in this case we DON'T rely on the ordering of the
>>> nodes. The inner<plan> nodes have child nodes which contain their
>>> relationship to the parent.
>>>
>
>
>> Not in the case of Append nodes, but I fail to see a problem there, so...
>>
>
> The order of Append child nodes is in fact significant. If this
> representation loses that information then it needs to be fixed.
> However, is it really so bad to be relying on node order for this?
>
>
>
No, if there is a genuine sequence of items then relying on node order
is just fine. My earlier (mistaken) reference was to possibly relying on
node order for a non-sequence relationship.
cheers
andrew