RE: NOLOGGING

DELETE is not a finction that NOLOGGING has any effect on. You can't reduce the amount of redo generated in a delete by making the object NOLOGGING. It is a common misconception :-) that NOLOGGING pertains to all types of DML and DDL. Please consult the following section of the Concepts Manual:

http://otn.oracle.com/docs/products/oracle8i/doc_library/817_doc/server.817/a76965/c21dlins.htm#4418

--
Jeremiah Wilton
http://www.speakeasy.net/~jwilton

On Tue, 26 Jun 2001, Ramon Estevez wrote:



> As I am concerned, the only redo information it generates is related

> to the system tablespace, the one refering to the manage of the extents.

>

> -----Mensaje original-----

> De: root_at_fatcity.com [mailto:root_at_fatcity.com]En nombre de Gaja Krishna Vaidyanatha

>

> That is not true. Setting NOLOGGING at the object

> level only reduces the amount of redo generated for

> bulk INSERT operations with the /*+ APPEND */ hint,

> certain partition administration operations and of

> course during the creation of the object itself. It

> does not eliminate generation of redo during a delete

> operation.

>

> Attached is a sample output from a couple of delete

> commands, one with LOGGING and the other with

> NOLOGGING:

>

> --- Ramon Estevez <com.banilejas_at_codetel.net.do> wrote:

> >

> > Yes, you should get a improve performance due to the

> > nologging option in the

> > delete wont write redo log information.

> >

> > -----Mensaje original-----

> > De: root_at_fatcity.com [mailto:root_at_fatcity.com]En

> >

> > If I have a delete which I know I never want to roll

> > back, can I get a

> > performance gain by using the nologging option ?

> >

> > Delete nologging is not, to the best of my

> > knowledge, documented on 8.1.6

> > ... but the query executes OK.

> >

> > However, when I used autotrace, the delete with

> > nologging seemed to give the

> > same or worse results than a normal delete.


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Author: Jeremiah Wilton
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