Re: database migration

From: Haroon A. Qureshi <>
Date: Tue, 10 Feb 2009 08:50:35 -0800 (PST)
Message-ID: <>

Thanks for the feedback.  Since we are moving from AIX to Linux,  I can't use transportable tablespaces without doing a convert or RMAN.  So I'm forced to use export/import datapump. 


There are a number of documents on metalink regarding using exp/imp with named pipes. 


  • On Tue, 2/10/09, Howard Latham <> wrote: From: Howard Latham <> Subject: Re: database migration To: Cc: "Milton, Eric" <>, Date: Tuesday, February 10, 2009, 10:02 AM

I did a migration from NT to Linux The DB was approx 600gig.

I used transportable tablespaces. The physical copy was what slowed me down it took approx 18 hours.

The other problem was test windows. Do yourself a favour and beg borrow or steal a box / disk array you can practice on!.

Howard Latham

2009/2/10 Michael Fontana <>

Are you talking about using datapump and pipes?

I am not familiar with using pipes with traditional export/import.  If

it's possible, can you please reference an article or manual that details

this method?


-----Original Message-----

From: Milton, Eric []

Sent: Monday, February 09, 2009 5:47 PM


Subject: RE: database migration

 In a situation where I did not want to write scripts I used a pipe to

export/import with performance that was exceptional. You should be able to

use many of the standard exp/imp commands. The time on a slow Unix box,

slow, to move 10,000,000 rows in a 26 column table, was about 15 minutes.

One very nice feature is the "tiny" amount of disc space you need.

-----Original Message-----

From: []

On Behalf Of Michael Fontana

Sent: Monday, February 09, 2009 1:52 PM


Subject: RE: database migration

I would definitely be engaging Oracle support to assist with your

migration, or at least offer suggestions and best practice methodologies

since Oracle applications are involved.  We found this out when doing an

Oracle BI and datawarehouse migration!

There are many differences in patch sets and release levels of Oracle

applications and supporting database between your platforms.  You may also

have to consider what might be running during a phased migration on the

source that could impact timings (IE - you are migration DB3 while DB1 and

DB2 are doing heavy batch processing and they slow it down).

I have heard of some people having success with logical sql-apply

methodologies for migrating databases across platforms, but have no

experience with it.

Hopefully we have started the ball rolling and you'll get some other

valuable responses.

-----Original Message-----

From: Haroon A. Qureshi []

Sent: Monday, February 09, 2009 2:44 PM

To:; Michael Fontana

Subject: RE: database migration

Thanks Michael.  We are running Oracle Applications 11.5.9 and are moving

to new dell servers with 2 dual core CPUs with 32gb of memory running

Oracle Enterprise linux 4.7.  it is a 10g database (

Your initial impression about timing is correct.  we are on an aggressive

schedule and don't have the time to write the scripts and test them out.

however, if we had a ball park idea of what the savings would be, if any,

of using rman vs expdp/impdp, we may be able to justify the extra time

spent on it.

the readonly issue is a big concern, depending on how long it will take to

export the db or use rman to move it over.  we are also planning on moving

to ASM during the migration.

Thanks in advance for your help.


  • On Mon, 2/9/09, Michael Fontana <> wrote:

> From: Michael Fontana <>

> Subject: RE: database migration

> To:,

> Date: Monday, February 9, 2009, 2:28 PM

> There are just too many variables to give you a ballpark

> figure.   What is

> the configuration of your current implementation versus

> your target

> hardware?  What version(s) of products are you currently

> running?


> My initial impression of your statement about not having

> enough time is

> that you're going to have to test out your scripts and

> methodologies

> regardless of any estimates you might collect from external

> sources.  You

> simply have to include timing these "rehearsals"

> you'll be doing to give

> yourself a fair chance of being able to predict the

> actuals.


> Be prepared for some extended downtime - the rman convert

> methodology

> requires that the source tablespaces are in READONLY mode

> during the

> backup process.  If there are any relationships between

> objects within

> them, they'll all have to be in that mode for the

> duration.


> This is pretty much the case with expdp/impdp as well,

> although your

> mileage may vary!




> -----Original Message-----

> From:

> []

> On Behalf Of Haroon A. Qureshi

> Sent: Monday, February 09, 2009 2:09 PM

> To:

> Subject: database migration


> Hello,


> We are doing a database migration from AIX to Linux.  Our

> database is

> 600gb.  Has anyone used the rman convert database method to

> migrate the

> database?  Do you have any timings you can share,

> especially compared to

> expdp/impdp?  Unfortunately, I don't have the luxury of

> time to try it out

> myself.


> Thanks in advance!

> Haroon

> --




Howard A. Latham

Received on Tue Feb 10 2009 - 10:50:35 CST

Original text of this message