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From "Chip Hartney (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-4032) Record not found in some SQL
Date Fri, 30 Jan 2009 15:05:59 GMT

    [ https://issues.apache.org/jira/browse/DERBY-4032?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12668890#action_12668890

Chip Hartney commented on DERBY-4032:

As I think about it more, I realize that the "corruption" in my prior scenarios may have actually
occurred during the reload process, itself.  If that is the case, then my patch would be of
no use as it is designed to fix the index before commencing with the reload.  That raises
the criticality of this problem as far as I'm concerned.

And I use the term "corruption" loosely.  As I understand it, one of the following is the
case (either of which is a bug):
 o The index is not supposed to have duplicate records in it, but does.
 o The index is allowed to have duplicate records, but the b-tree logic does not properly
allow for that.

> Record not found in some SQL
> ----------------------------
>                 Key: DERBY-4032
>                 URL: https://issues.apache.org/jira/browse/DERBY-4032
>             Project: Derby
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions:
>         Environment: Windows XP
>            Reporter: Chip Hartney
>         Attachments: OrderEntryDB-base.zip, OrderEntryDB-seg0-part1.zip, OrderEntryDB-seg0-part2.zip,
OrderEntryDB-seg0-part3.zip, OrderEntryDB-seg0-part4.zip, OrderEntryDB-seg0-part5.zip, OrderEntryDB-seg0-part6.zip,
> Per discussion at http://www.nabble.com/Record-not-found-in-some-SQL---Bug--td21700110.html...
> I have a "Product" table with a "Num" column that contains a record that is only accessible
by some SQL and not others.  I have tested this by JDBC access from my Java app as well was
from IJ directly.
> ij> select "Num", length("Num") as "Len" from app."Product" where "Num" like 'HG1549%';
> Num            |Len
> ----------------------------
> HG15490        |7
> HG15493        |7
> HG15497        |7   <== Found as expected
> HG15499        |7
> 4 rows selected
> ij> select "Num" from app."Product" where "Num" = 'HG15490';
> Num
> ----------------
> HG15490  <== Found as expected
> 1 row selected
> ij> select "Num" from app."Product" where "Num" = 'HG15493';
> Num
> ----------------
> HG15493  <== Found as expected
> 1 row selected
> ij> select "Num" from app."Product" where "Num" = 'HG15499';
> Num
> ----------------
> HG15499  <== Found as expected
> 1 row selected
> ij> select "Num" from app."Product" where "Num" = 'HG15497';
> Num
> ----------------
> 0 rows selected  <== Not found!!!
> What could possibly hide the 'HG15497' record from the last SELECT?
> And it's not just a matter of equality versus inequality...as the following SQL does
return the record:
= P."Num" WHERE I."STYLE" = 'HG15497'; 

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