Re: BUG #14940: Duplicated records inspite of primary key and uniqueconstraint - Mailing list pgsql-bugs

From Tomas Vondra
Subject Re: BUG #14940: Duplicated records inspite of primary key and uniqueconstraint
Date
Msg-id affd00c7-d068-bfb9-41ce-57759c385390@2ndquadrant.com
Whole thread Raw
In response to BUG #14940: Duplicated records inspite of primary key and uniqueconstraint  (sergey.frolov@smetarik.ru)
Responses Re: BUG #14940: Duplicated records inspite of primary key and uniqueconstraint  (Сергей А. Фролов<sergey.frolov@smetarik.ru>)
List pgsql-bugs
On 12/01/2017 01:45 PM, sergey.frolov@smetarik.ru wrote:
> The following bug has been logged on the website:
> 
> Bug reference:      14940
> Logged by:          sergey frolov
> Email address:      sergey.frolov@smetarik.ru
> PostgreSQL version: 9.6.6
> Operating system:   Windows 10, 64
> Description:        
> 
> Hi, I have noticed duplicated records inspite of primary key and unique
> constraint.  
> 
> select version ()
> PostgreSQL 9.6.6, compiled by Visual C++ build 1800, 64-bit
> 
> The DDL is 
> CREATE TABLE nb.nb_basedtl
> (
>   id integer NOT NULL, 
>   base_id integer NOT NULL, 
>   norm_id integer NOT NULL, 
>   ...
>   CONSTRAINT pk_nb_basedtl PRIMARY KEY (id),
>   CONSTRAINT unq_nb_basedtl UNIQUE (norm_id, base_id),
>   ....
> 
> The problem is
> 
> select ctid,xmin,xmax, id, base_id, norm_id from nb.nb_basedtl where id =
> 11658502 ;-- expected ONE row 
> 
> (0,49);364507;0;11658502;269;46203
> (0,49);370881;0;11658502;269;46203
> (0,49);370882;0;11658502;269;46203
> 
> 
> select (select count(1) from nb.nb_basedtl), (select count(1) from (select
> id, count(1) from nb.nb_basedtl  group by id having count(1) > 1 ) t )
> 3586895;50
> 

Seems like some sort of data corruption, but it's impossible to say how
the database got into this state. You'll have to tell us more about the
system.

Did it crash in the past?

What sort of filesystem/storage does it use?

How old is the database/which PostgreSQL versions was it running (e.g.
it may be a new system loaded last week, or it may be an old system
started on 9.0 and upgraded using pg_upgrade).

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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