Re: Is data import from Oracle table to Postgres table in Ora2pg consecutive or random?

From: DAVID ROTH <adaptron(at)comcast(dot)net>
To: Daniel Gustafsson <daniel(at)yesql(dot)se>, Matthias Apitz <guru(at)unixarea(dot)de>
Cc: pgsql-general(at)lists(dot)postgresql(dot)org
Subject: Re: Is data import from Oracle table to Postgres table in Ora2pg consecutive or random?
Date: 2023-09-12 13:24:14
Message-ID: 1540456242.525885.1694525054393@connect.xfinity.com
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I have not tried this in a while but I think a SELECT with a "hint" will return rows in the order of the index in the hint. This does NOT work for distributed queries.

> On 09/12/2023 9:10 AM EDT Daniel Gustafsson <daniel(at)yesql(dot)se> wrote:
>
>
> > On 12 Sep 2023, at 14:26, Matthias Apitz <guru(at)unixarea(dot)de> wrote:
> >
> > El día martes, septiembre 12, 2023 a las 02:19:19 +0200, Peter J. Holzer escribió:
> >
> >>> - Or can we add additional parameters to the ora2pg.conf file to control this
> >>> process and ensure that the data is imported sequentially, following the
> >>> primary key from smallest to largest?
> >
> > AFAIK, a simple SELECT in PostgreSQL without an ORDER BY will return the rows
> > in random order.
>
> It will return the rows in some order, without guarantees about randomness or
> asc/desc ordering. Any query which relies on ordering, whichever is wanted,
> should include an ORDER BY clause.
>
> --
> Daniel Gustafsson

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