Re: speed this up?

  • From: "Rich Jesse" <rjoralist@xxxxxxxxxxxxxxxxxxxxx>
  • To: "oracle-l-freelists" <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 22 Oct 2008 21:45:42 -0500 (CDT)

I was thinking the best way is to not create the temp table at all.  Reminds
me of the way SQL Server works... <shudder>

Rich

> Hi Guang
>   You may have to do self join. I don't know about selectivity of
> 'column2> some_value' predicate and so, this rewritten version could be
> worse. Also, make sure that it uses index on column2 using explain plan..
>
> create table tmp_table nologging as
> select distinct column1 from table1 t1 where column2 > some_value
> and exists (
>     select 1 from table1 t2 where t1.column1 =  t2.column1 and
> t2.column2> some_value
>      and t1.row_id != t2.row_id)
> ;
>
> Cheers
> Riyaj

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