Re: Oracle to postgres migration

Hi Rajesh

Rajesh Kumar <rajeshkumar(dot)dba09(at)gmail(dot)com> schrieb am Mo. 27. Jan. 2025 um
11:13:

> With regards to lo, is there any difficulty if we have rowsize > 1gb
>
For most cases, I would recommend to migrate lobs > 1gb into
pg_largeobjects. The way of accessing those lobs will change (also for the
application)
This could be done with a bit of python scripting. I’m not sure if there is
a option within ora2pg meanwhile.

Regarding the sizes in general, you can check out below article:
https://www.enterprisedb.com/postgres-tutorials/postgresql-toast-and-working-blobsclobs-explained

Best regards
Raphael

> On Mon, 27 Jan 2025, 15:41 Rajesh Kumar, <rajeshkumar(dot)dba09(at)gmail(dot)com>
> wrote:
>
>> Thank you all. As mush as more info is always appreciated by dearest
>> admins
>>
>> On Mon, 27 Jan 2025, 15:40 Ron Johnson, <ronljohnsonjr(at)gmail(dot)com> wrote:
>>
>>> I migrated a 12TB Oracle db that was mostly LOB objects into an 8TB PG
>>> database. LOBs loaded into bytea columns.
>>> One thing which I did not do, but should have, was have ora2pg convert
>>> NUMBER(38,0) values to BIGINT.
>>>
>>> We just used ora2pg to convert data; the app developer rewrote all of
>>> the stored procedures, functions, triggers, etc.
>>>
>>> On Mon, Jan 27, 2025 at 4:31 AM Rajesh Kumar <
>>> rajeshkumar(dot)dba09(at)gmail(dot)com> wrote:
>>>
>>>> Size is 300gb, have lob objects. I prefer ora2pg. Does EDB MTK costs?
>>>>
>>>> Mostly I need to know what are all the things I need to ask oracle
>>>> people to start withj
>>>>
>>>> On Mon, 27 Jan 2025, 14:52 Julien Rouhaud, <rjuju123(at)gmail(dot)com> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> On Mon, Jan 27, 2025 at 02:42:22PM +0530, Rajesh Kumar wrote:
>>>>> > Hi team,
>>>>> >
>>>>> > I am trying to migrate from oracle to postgres.
>>>>> >
>>>>> > I have been asked to provide an estimation for effort days. Anybody
>>>>> has any
>>>>> > document related to estimation? And steps.
>>>>> >
>>>>> > Where do I start with? Anybody has any documentation related to
>>>>> ora2pg
>>>>> > migration ?
>>>>>
>>>>> ora2pg is probably the best tool for your task. And yes it does
>>>>> provide
>>>>> estimates for the migration efforts, see
>>>>> https://ora2pg.darold.net/documentation.html#Migration-cost-assessment
>>>>> .
>>>>>
>>>>> In general the ora2pg documentation is really good, you should find
>>>>> the answer
>>>>> to all your questions there.
>>>>>
>>>>
>>>
>>> --
>>> Death to <Redacted>, and butter sauce.
>>> Don't boil me, I'm still alive.
>>> <Redacted> lobster!
>>>
>>