Re: Migration from HPUX to Linux

Hello,

Some years ago I had a similar problem. Moving a table with a big lob from AIX to Linux. 11g database.
We have to try to parallelize the process.

If you are using basic file, these should help. Luckily, I saved the original post that helps me:

• LOB Basic File in parallel --

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  -- https://www.linkedin.com/pulse/optimising-lob-export-import-performance-via-oracle-datapump-arya/

Thanks to the author for this trick!!

Hope this helps!

Em qua., 23 de out. de 2024 às 18:14, pier paolo Bruno <pbrunoster_at_gmail.com> escreveu:

> Hi,
> I have to move a database of 1,5gb from hpux 11.2.0.1 to a linux
> machine with 19.24 with oracle restart (different endianess ) .
> The database is formed by 500gb of data and lob, a single lob of 700b
> and indexes. The single lob table is not on separated tablespace. I
> discarded the use of transportable tablespace because for installing
> 11.2.0.4 on OL 8.10 i need a patchset and a patch that i can not
> download :
> Requirements for Installing Oracle Database/Client 11.2.0.4 on OL8 or
> RHEL8 64-bit (x86-64) (Doc ID 2988626.1).
> It would also be a serious problem to put the source in readonly for
> the time of the datafile copy, it would last at least 8 hours and for
> a health system it is a problem (source system is old and slow ) . I
> could ask a window once , but we evaluated that with datapump i can do
> all the test i want without giving impact, in the window 16pm 7 am .
> I can do the migration in 2 steps ,so our idea is to export everything
> without the big lob table and to do it afterwords. Applications can
> survive with this table empty for what we know till now. The hpux
> machine is quite slow but in an initial test i managed to export with
> datapump and import everything in 13 hours and for me it is ok.
> The problem is how to proceed with the 700gb lob. Exporting on
> filesystem seems quite slow, i had to kill the export because i could
> i had a window from 16pm to 7am and only 200 were exported . I know
> that when i will do the migration i will be able t o let it going but
> i was asking if it was the best way to do the task. Lobs are
> basicfiles.
> I also try a test like this :
> create global temporary table tb1 ;
> insert into tb1 select * from table_at_remote where rownum< 5000;
> insert into final_table select * from tb1 ;
> It worked but it took 20 minutes for 5gb .
> Surely i could study a way to cluster values of primary key in plsql
> and to try to build a manual "parallelism" mechanism, but i don't know
> if at the end i go faster and i have not a test envirorment .
> I can not modify the source envirorment because it is a system of
> pubic health service and so we can touch anything .
> I was wondering to try impdp with network link but i am not sure if it
> works with basicfile lob ( if i can i try tomorrow but i am allocated
> on more than one project ) .
> Have you a different idea to test ?
> Any hint is appreciated
>
> Regards
> Paolo
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

-- 
Gabriel Hanauer

--
http://www.freelists.org/webpage/oracle-l