nologging in oracle

1. nologging option is used for bulk insert to speed up operation and improve performance by reduce redo generation.

2. It will not work for update and delete.

3. for insert, /* append */ hint must be used and talbe must be nologging mode

4. it is very useful for create table from existing resource so that no recovery needed if instance crashed.

EXP: create table tt nologging as select * from testtable.

5. alter table move  and alter index build just like APPEND.

6. table from ASK TOM

Tom's Table:
------------

Table Mode    Insert Mode     ArchiveLog mode      result
-----------   -------------   -----------------    ----------
LOGGING       APPEND          ARCHIVE LOG          redo generated
NOLOGGING     APPEND          ARCHIVE LOG          no redo
LOGGING       no append       ""                   redo generated
NOLOGGING     no append       ""                   redo generated
LOGGING       APPEND          noarchive log mode   no redo
NOLOGGING     APPEND          noarchive log mode   no redo
LOGGING       no append       noarchive log mode   redo generated
NOLOGGING     no append       noarchive log mode   redo generated

reference:
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:5280714813869
http://jakub.wartak.pl/blog/?page_id=107