Re: long to clob conversion redo size and new table size

"Grzegorz" <grzegorzof_at_interia.pl> a écrit dans le message de news: h4kudv$r3p$1_at_news.task.gda.pl...
> Mark D Powell pisze:
>> On Jul 27, 12:19 pm, Grzegorz <grzegor..._at_interia.pl> wrote:
>>> Hi,
>>> I've got 300GB table t1 with 2 columns:
>>>
>>> id number primary key,
>>> some_data long
>>>
>>> currently 70 mln rows.
>>> When I'm doing to_lob conversion via:
>>>
>>> insert /*+ APPEND NOLOGGING */ into t2 select id, to_lob(some_data)
>>> some_data from t1 where id between 1 and 2222222;
>>>
>>> table t2 clob is defined as 8kb chunk in MSSM tablespace (uniform size
>>> 1M)
>>>
>>> a 63MB redolog is switched every 18 seconds.
>>> My question is what is in redo ?
>>> The only think which comes to my mind is lob index maintenance but
>>> is that true ? Database is 9.2.0.8 and NOARCHOVELPG mode.
>>> Second question :
>>> How to minimize ne wtable (t2) size (table is insert/select only).
>>>
>>> Regards.
>>> Grzegorz
>>
>> LOB data is forward recoverable just like any other data. The LOB
>> inserts are being logged.
>
> Even with NOLOGGING hint ?
> How to minimize redo size in that case ?
> Regards.
> Grzegorz
Received on Mon Jul 27 2009 - 15:03:31 CDT