maria-developers team mailing list archive

[Elena Stepanova <elenst@xxxxxxxxxxxxxxxx>]

Hi Pantelis,

On 06/21/2016 06:28 PM, Pantelis Theodosiou wrote:
> According to this post at Stack Overflow, MariaDB 10.1.10 gives wrong
> results (duplicate rows) for UNION DISTINCT while the UNION version
> gives correct ones.
>
> (notice the comment:
> http://dba.stackexchange.com/questions/141799/select-distinct-values-of-two-columns-as-single#comment268612_141800
> )
>
> The query in question is very simple:
>
> |SELECTa ASresult FROMtableX UNIONDISTINCTSELECTb FROMtableX ;|
>
> I couldn't find a related bug in the MDEV.
>
> Is this a known (or fixed) issue or should I go and add a bug report/

Yes, please create a bug report. Importantly, please put there the exact 
table definition (output of SHOW CREATE TABLE tableX) and output of SHOW 
VARIABLES from the session where the problem occurs.

If you have access to the database via a command-line client, please 
also paste the unabridged output of executing the following:

show table status like 'tableX';
check table tableX;
select * from tableX;
SELECT SQL_NO_CACHE a AS result FROM tableX UNION DISTINCT SELECT b FROM 
tableX;

If you don't have the command-line client, please just provide results 
of the queries in any form.


Thanks,
Elena Stepanova

> Pantelis Theodosiou
>
>
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