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

From: duc hiep ha <haduchiep(at)googlemail(dot)com>
To: pgsql-general(at)lists(dot)postgresql(dot)org
Subject: Is data import from Oracle table to Postgres table in Ora2pg consecutive or random?
Date: 2023-09-12 11:17:46
Message-ID: CAM2ukhKE5FJz-j8ySF9-Yk=1L0OWr-p8M3dovKP6N_xcFV+VWw@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

> Hello friends,
>
> I want to migrate a large Oracle table to PostgreSQL, which is
> approximately 200GB in size and includes a LOB segment. This table has a
> primary key column named "ID," which increments by one unit (similar to a
> sequence). During the migration of this large table, sometimes the process
> terminates prematurely (due to network issues, etc.). As a result, I have
> to restart the import process either from the beginning or by using a WHERE
> clause in the ora2pg configuration file to import the remaining data from
> where it was previously terminated.
>
> However, I've noticed that the import process in ora2pg doesn't seem to
> follow a consecutive order, starting from a small ID number and progressing
> to a larger ID number. Instead, it appears to import data randomly from
> various rows of the table. This makes it impossible to continue importing
> data from the point where it was terminated using a WHERE clause in ora2pg.
>
> My questions are:
>
> - Is it correct that ora2pg imports data from the Oracle table to the
> PostgreSQL table randomly and not sequentially from a smaller ID to a
> larger ID?
> - 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?
> Thank you,
> Hans
>

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Graeme 2023-09-12 11:49:57 pg_update and encoding
Previous Message Graeme 2023-09-12 10:51:55 Re: Upgrade problem