Re: Array assignment behavior (was Re: [ADMIN] Stored procedure

Yep, that definitely threw me the first time I encountered it.

Paul B. Anderson wrote:
> It seems that the suggestion to fill intermediate positions with NULLs
> would be preferable to the current behavior.
>
> I know of no requirement to populate arrays in sequence in any other
> language so I think other programmers would be surprised too by the
> current behavior.
>
> Paul
>
>
> Tom Lane wrote:
>> [ expanding this thread, as it now needs wider discussion ]
>>
>> "Paul B. Anderson" <paul.a@pnlassociates.com> writes:
>>
>>> Actually, I was not filling all of the arrays in sequential order.  I
>>> added code to initialize them in order and the function seems to be
>>> working now.  Is that a known problem?
>>>
>>
>> Well, it's a documented behavior: section 8.10.4 saith
>>
>>     A stored array value can be enlarged by assigning to an element
>>     adjacent to those already present, or by assigning to a slice
>>     that is adjacent to or overlaps the data already present.
>>
>> Up to 8.2 we didn't have a lot of choice about this, because without any
>> ability to have nulls embedded in arrays, there wasn't any sane thing to
>> do with the intermediate positions if you assigned to an element not
>> adjacent to the existing range.  As of 8.2 we could allow assignment to
>> arbitrary positions by filling the intermediate positions with nulls.
>> The code hasn't actually been changed to allow that, but it's something
>> we could consider doing now.
>>
>> Comments?
>>
>>             regards, tom lane
>>
>> ---------------------------(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
>>
>> .
>>
>>


--
erik jones <erik@myemma.com>
software development
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