Re: parallel datapump export to multiple directoy objects
Date: Wed, 20 Aug 2014 10:46:32 -0500 (CDT)
Message-ID: <a35a732eed29bf595afb7a79f311db30.squirrel_at_society.servebeer.com>
> I have a rather short window to do a 90 gb datapump full db export. Going
> to use parallel. My understanding is that when you do a parallel expdp,
> oracle creates 1 file for each parallel slave. I have several different
> disk devices loaded as mount points. Is it possible to use multiple
> directory objects in one expdp to spead out the IO?
The docs suggest that only a single DIRECTORY parameter can be given to expdp, so I'd say "no".
I've got my 110+GB expdp elapsed time dropped from 20 min to <5 minutes (POWER7 LPAR w/XIV storage) by watching the export run via EM12c ("Cloud Control"). It was very obvious that the largest table took 5x longer than every other object combined. Further examination of the SQL used for pulling the large table showed that expdp decided to use only 4 of the 16 parallel threads for dumping it out.
So I ran two exports. Each has a DOP of 16. The first excludes that big table and the second is solely for the big table. Even running them sequentially, the elapsed time dropped by a factor of 4 or 5.
Barring faster storage (the XIV was giving me up to 4GB/s!), perhaps some creative exporting could help you out here.
HTH! GL! Rich
-- http://www.freelists.org/webpage/oracle-lReceived on Wed Aug 20 2014 - 17:46:32 CEST