long to clob conversion redo size and new table size

From: Grzegorz <grzegorzof_at_interia.pl>
Date: Mon, 27 Jul 2009 18:19:58 +0200
Message-ID: <h4kk3i$6pk$1_at_news.task.gda.pl>


          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 and NOARCHOVELPG mode. Second question :
How to minimize ne wtable (t2) size (table is insert/select only).

Grzegorz Received on Mon Jul 27 2009 - 11:19:58 CDT

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