Re: pg_dump restores as expected on some machines and reports duplicate keys on others

Hi Shaheed,

As pointed above by Adrian Klaver, I suspect that you did multiple attempts
that caused Database Already Exists. ( There must be data in the tables,
which the next attempt is trying to write again) . I can't think of any
scenario where restoration succeeds on one environment and fails on
another, if there were some locale difference then it must have failed with
a different reason, not the duplicates

Perform a clean up and try again. Hope it succeeds.

Regards,
Muhammad Ikram
Bitnine Global.

On Sun, Jun 23, 2024 at 2:59 AM Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>
wrote:

> On 6/22/24 10:01, Shaheed Haque wrote:
> > Hi,
> >
> > I am using Postgres 14 on AWS RDS and am seeing the output of pg_dump be
> > restored as expected by pg_restore on some database instances, and fail
> > with reports of duplicate keys on other database instances:
> >
> > * My deployments are always a pair, one "logic VM" for Django etc and
> > one "RDS instance". The psql client runs on the logic VM. The
> > Postgres version is the same in all cases; psql reports:
> >
> > o psql (14.12 (Ubuntu 14.12-0ubuntu0.22.04.1), server 14.9)
> >
> > * The pg_restore is done using the same script in both cases.
> > * In the failing cases, there are always the same 26 errors (listed in
> > detail below), but in summary, 3 distinct "child" tables complain of
> > a duplicate id=1, id=2 and id=3 respectively.
> > * These "child" tables are FK-related via some intermediate table to a
> > top level table. They form a polymorphic set. There are other
> > similar child tables which do not appear to be affected:
> > o polymorphicmodel
> > + companybankdetail
> > # companybankdetailde
> > # companybankdetailgb <<< 1 duplicate, id=2
> > # companybankdetailus
> > + companypostaldetail
> > # companypostaldetailde
> > # companypostaldetailgb <<< 1 duplicate, id=1
> > # companypostaldetailus
> > + companytaxdetail
> > # companytaxdetailde
> > # companytaxdetailgb <<< 1 duplicate, id=3
> > # companytaxdetailus
> > + ...
> > + several other hierarchies, all error free
> > + ...
> > * I've looked at the dumped NNNN.dat files but they contain no
> duplicates.
> > * The one difference I can think of between deployment pairs which
> > work ok, and those which fail is that the logic VM (i.e. where the
> > psql client script runs) is the use of a standard AWS ubuntu image
> > for the OK case, versus a custom AWS image for the failing case.
> > o The custom image is a saved snapshot of one created using the
> > standard image.
> >
> > Why should the use of one type of VM image versus another cause
> > pg_restore to hallucinate the duplicate records?
> >
>
> 1) Show the complete pg_restore script.
>
> 2) The first issue is related to trying to create a database that
> already exists. Does that database have data in it?
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com
>
>
>
>

--
Muhammad Ikram