Re: Doing large sort in RAM - sort workarea manipulation
- From: Timo Raitalaakso <rafu@xxxxxx>
- To: oracle-l@xxxxxxxxxxxxx
- Date: Sat, 12 Nov 2011 23:24:56 +0200
You found the Tapio Lahdenmäki recommended second star index and hinted
that correctly to avoid sorting. Something I rediscovered from Richard
Foote night quiz
http://rafudb.blogspot.com/2011/09/avoid-temp-usage-while-table-reorg.html
To do that in parallel might be tricky if you need the results serially
out of database to some ETL tool. Should there be a possibility to do
insert into select in parallel with order by using the possibilitises of
partition wise doing stuff. Tony Hasler is talking of such partition
wise join in his blog post
http://tonyhasler.wordpress.com/2010/03/10/parallel-query-distribution-methods/.
I would quess that requires changing your ETL to be done inside database
and the partitioning of source and target to be similar.
--
Rafu
12.11.2011 20:38, GG kirjoitti:
> On 11/12/11 18:45, Jonathan Lewis wrote:
>> Unless you have defined ID to be NOT NULL (or added a not null constraint, or
>> add a predicate "id is not null" to the query) then it isn't possible for the
>>
>> SQL> select /*+ INDEX(t idx_id) */ * from sort_px t order by id;
>>
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