Neighter the sql spec nor the derby manual promises this behavior
(ordering of group by
clause without order by). So I don't think this is a deviation from the
existing behavior.
anurag
Anurag shekhar wrote:
> Unique constraint on non nullable fields still act like a unique index
> (because there is no null value) but internally they are backed by non
> unique indexes with uniqueWhenNotNull attribute.
> anurag
>
> Mike Matrigali wrote:
>> I thought from functional spec and ongoing discussion that behavior
>> of unique constraint on non-nullable columns would be unchanged. So
>> this
>> constraint should still be backed by a unique index.
>>
>> Anurag Shekhar (JIRA) wrote:
>>> [
>>> https://issues.apache.org/jira/browse/DERBY-3330?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12573032#action_12573032
>>> ]
>>> Anurag Shekhar commented on DERBY-3330:
>>> ---------------------------------------
>>>
>>> dml019 test group by clause of unique constraint. When unique
>>> constraint was backed by unique index, distinct scan was used but
>>> after making it non unique constraint this was not the case so the
>>> results are not ordered.
>>> I have checked the test suite from nist web site and it mandates
>>> only number of rows and not their sequence.
>>>> provide support for unique constraint over nullable columns
>>>> -----------------------------------------------------------
>>>>
>>>> Key: DERBY-3330
>>>> URL: https://issues.apache.org/jira/browse/DERBY-3330
>>>> Project: Derby
>>>> Issue Type: New Feature
>>>> Components: Store
>>>> Affects Versions: 10.4.0.0
>>>> Environment: all
>>>> Reporter: Anurag Shekhar
>>>> Assignee: Anurag Shekhar
>>>> Attachments: BTreeController.diff,
>>>> derby-3330-testcase.diff, derby-3330.diff, derby-3330v2.diff,
>>>> derby-3330v3.diff, derby-3330v4.diff, derby-3330v5.diff,
>>>> derby-3330v6.diff, derby-3330v7.diff, derby-3330v8.diff,
>>>> derby-3330v9.diff, FunctionalSpec_DERBY-3330-V2.html,
>>>> FunctionalSpec_DERBY-3330.html,
>>>> UniqueConstraint_Implementation.html,
>>>> UniqueConstraint_Implementation_V2.html,
>>>> UniqueConstraint_Implementation_V3.html
>>>>
>>>>
>>>> Allow unique constraint over nullable field. Right now derby
>>>> support unique constraint only over not null columns.
>>>
>>
>
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