db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Bryan Pendleton (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-2526) Wrong query results due to column ordering in UNION view
Date Sat, 28 Apr 2007 22:57:15 GMT

    [ https://issues.apache.org/jira/browse/DERBY-2526?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12492523
] 

Bryan Pendleton commented on DERBY-2526:
----------------------------------------

I tried various experiments toward alternates #1 and #2 from the previous
comment, and only succeeding in creating non-operational code. These
sections of the SelectNode code seem delicate, and the code can't 
be re-arranged easily; it all seems to work in exactly this order.

Now I'm thinking I should investigate the transitive closure code more
carefully, to see if there is a way to revise it so that it isn't so sensitive
to the column re-ordering but rather can recognize transitive closures
based on the original expressions.

> Wrong query results due to column ordering in UNION view
> --------------------------------------------------------
>
>                 Key: DERBY-2526
>                 URL: https://issues.apache.org/jira/browse/DERBY-2526
>             Project: Derby
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 10.0.2.1, 10.1.3.1, 10.2.2.0, 10.3.0.0
>            Reporter: Bryan Pendleton
>         Assigned To: Bryan Pendleton
>         Attachments: badQuery.log, derby-2526.sql, DistinctTestNotes.txt, firstTryPatch.diff,
goodQuery.log
>
>
> I think both select statements in the attached repro script should return 1 row, but
in fact the first statement returns 1 row and the second returns zero rows.
> The only difference between the two statements is that the columns in the UNION view
are listed in a different order (bvw vs. bvw2).
> This seems like a bug to me; the order of the columns in the view definition shouldn't
matter, should it? 
> As Army noted on the derby-dev list, the fact that this reproduces with 10.0 means that
it is not caused by some of the 10.2 optimizer changes. Something else is going wrong.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message