RE: index doesn't contain duplicates

  • From: TESTAJ3@xxxxxxxxxxxxxx
  • To: Richard.Goulet@xxxxxxxxxxx
  • Date: Tue, 9 Jun 2009 14:31:21 -0400

you could use the dump function on the values to see if they are truly the 
same.

joe

_______________________________________
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From:
"Goulet, Richard" <Richard.Goulet@xxxxxxxxxxx>
To:
<Josh.Collier@xxxxxxxxxxxx>, <mark.powell@xxxxxxx>, 
<oracle-l@xxxxxxxxxxxxx>
Date:
06/09/2009 02:23 PM
Subject:
RE: index doesn't contain duplicates
Sent by:
oracle-l-bounce@xxxxxxxxxxxxx



Josh,
 
    One question & this one has taken me to the cleaners more times that 
I'd like to admit.  The two rows that "appear" to be the same, are they of 
the same length?  Here's an example of what I mean:
 
    Row1: 'DATAVALUE'
    Row2: 'DATAVALUE '
 
There is a very slight difference, in this case a trailing space that 
really does make the two rows different.  Other characters that can cause 
similar problems is anything in the extended ascii character set which 
will show up like spaces.
 
Dick Goulet 
Senior Oracle DBA 
PAREXEL International 
 

From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] 
On Behalf Of Josh Collier
Sent: Tuesday, June 09, 2009 2:12 PM
To: mark.powell@xxxxxxx; oracle-l@xxxxxxxxxxxxx
Subject: RE: index doesn't contain duplicates

Version 9208
 
The way the table was created was this..
 
Table was created with a CTAS
Non-unique index was built 
Primary key was built on a column, specifying index created in step2. 
Enable novalidate. The data in question was inserted after the primary was 
in place.
 
 
 
The plan that produces the incorrect results is a fast full scan on the 
non-unique index
The plan that produces the correct result is a full tablescan on the 
table.
 
We 
 
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] 
On Behalf Of Powell, Mark D
Sent: Tuesday, June 09, 2009 10:22 AM
To: oracle-l@xxxxxxxxxxxxx
Subject: RE: index doesn't contain duplicates
 
Yes, the full Oracle version would be nice plus the select with plan the 
produces the proper results and one that does not.
 
Things you can try:
 
Run analyze index validate
Run analyze table validate cascade (depending on results from above)
Drop and re-create index
 
 -- Mark D Powell -- 
Phone (313) 592-5148 
 
 

From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] 
On Behalf Of Josh Collier
Sent: Tuesday, June 09, 2009 12:11 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: index doesn't contain duplicates
All,
 
I have an table that has duplicate values for a column. I have a 
non-unique index on this column. When I run a query that uses a fast full 
scan to retrieve the rows, it only retrieves one of the two rows. When I 
force a full tablescan both of the rows come back. I have used all my sql 
tricks to try my best to determine if the value has trailining or leading 
non-printable characters and it doesn’t appear so. I have also moved the 
values into a varchar 11 field in another table, the value is 11 chars 
long. Both of the duplicate rows where accepted. Does anyone know of a bug 
or a reason why both of the rows wouldn’t appear in the index?
 
Thanks for your time,
Josh C. 


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