RE: Export of CLOB too slow ?!!

are you using expdp or exp?

-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Keith Moore
Sent: Thursday, August 24, 2006 10:51 AM To: premjhere_at_gmail.com
Cc: oracle-l
Subject: Re: Export of CLOB too slow ?!!

Are you running it over a (slow) network?

CLOBs are exported a row at a time instead of a block at a time, so there is a network round trip for each row. I learned this when I tried to export a database in Japan from the U.S. over a very slow network link. A small database, much smaller than yours would have taken over 20 hours.

Keith

> Friends,
>
> This is on oracle 10.2.0.1 / AIX5.3L on IBM P595 machine which
> has got 64 CPUs and ~200G RAM.
>
> Export of a 100GB schema in this database takes 11+ hours. The
> reason export being slow , I feel , is 32 out 118 tables have CLOB
> column. And the largest 2 tables (with CLOB) have 7 million
> (20G in size) and 3.5 million (10G in size) rows respectively.
>
> 15 million rows are with CLOB data of the total 23 million rows
> to be exported.
>
> Is the export expected to be this slow on such a hardware ?
> Read on the net that splitting the big clob tables based on primary key
> using QUERY parameter (of export) and running them in parallel
> would help. Is this is a proven method ? I need to test it though.
>
> Any other suggestions to speed up this export ? Thanks in advance.
>
> Regards | Jp.
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> http://www.freelists.org/webpage/oracle-l
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>
>

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