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

DAVID ROTH <adaptron@comcast.net>

From: DAVID ROTH <adaptron@comcast.net>
To: Daniel Gustafsson <daniel@yesql.se>, Matthias Apitz <guru@unixarea.de>
Cc: pgsql-general@lists.postgresql.org
Date: 2023-09-12T13:24:14Z
Lists: pgsql-general
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@yesql.se> wrote:
> 
>  
> > On 12 Sep 2023, at 14:26, Matthias Apitz <guru@unixarea.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