Re: de-dup process

  • From: Tony van Lingen <tony.vanlingen@xxxxxxxxxxxxxx>
  • To: ebadi01@xxxxxxxxx
  • Date: Thu, 14 Dec 2006 13:04:30 +1000

It may even be easier... You say "We are doing direct path load so no 
unique key indexes can be put on the table to take care of the 
duplicates". The utility guide (10gR2) however explicitly names unique 
constraints as a constraint that can be enforced during direct path loads:

>       Integrity Constraints
> All integrity constraints are enforced during direct path loads, 
> although not necessarily at the same time. |NOT| |NULL| constraints 
> are enforced during the load. Records that fail these constraints are 
> rejected.
> |UNIQUE| constraints are enforced both during and after the load. A 
> record that violates a |UNIQUE| constraint is not rejected (the record 
> is not available in memory when the constraint violation is detected).
(Utilities, B14215-01 chapter 11).

Did you actually try this?


A Ebadi wrote:

> We have a huge table (> 160 million rows) which has about 20 million 
> duplicate rows that we need to delete.  What is the most efficient way 
> to do this as we will need to do this daily?
> A single varchar2(30) column is used to identified duplicates.  We 
> could possibly have > 2 rows of duplicates.
> We are doing direct path load so no unique key indexes can be put on 
> the table to take care of the duplicates.
> Platform: Oracle 10G RAC (2 node) on Solaris 10.
> Thanks!
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