Re: Nologging clause

  • From: "Vishal Gupta" <vishal@xxxxxxxxxxxxxxx>
  • To: <wjwagman@xxxxxxxxxxx>
  • Date: Fri, 10 Apr 2009 06:01:13 +0100

Please keep in mind that of ig database is running in archivelog mode. Then any no logging operation puts those objects at risk until next full or inremental backup. In case of database failure, if previous backups of file are restored since there will not be any archivelogs for your no logging changes. It will result in corruption of affected data blocks. And your only chances of recovering would be to drop the table. Or in case of indexes, they would need to be rebuilt.



Cheers,
Vishal Gupta

On 1 Apr 2009, at 16:59, "William Wagman" <wjwagman@xxxxxxxxxxx> wrote:

Greg,

Again, thank you. The next question I have is in regards to deletes. Is it possible to do a direct path delete (does that even make sense)? As I mentioned this will be a repository for CAS tickets and they will be deleted at their expiration time. Is it possible to avoid generation of redo on a delete as well?

Thanks.

Bill Wagman
Univ. of California at Davis
IET Campus Data Center
wjwagman@xxxxxxxxxxx
(530) 754-6208

-----Original Message-----
From: Greg Rahn [mailto:greg@xxxxxxxxxxxxxxxxxx]
Sent: Tuesday, March 31, 2009 5:27 PM
To: William Wagman
Cc: oracle-l@xxxxxxxxxxxxx
Subject: Re: Nologging clause

This is correct.  The [NO]LOGGING only changes direct path operations.
That is, inserts with the /*+ APPEND */ hint.

So if you want NOLOGGING you need either:
- NO ARCHIVE LOG mode
- ARCHIVE LOG mode, NOLOGGING, and APPEND hint

On Tue, Mar 31, 2009 at 5:04 PM, William Wagman <wjwagman@xxxxxxxxxxx> wrote:
It appears that he is saying that if a table is set to nologging and my insert mode is append then even if archive logging is on no redo will be generated. I'm still not sure I am understanding this correctly but I take that to mean

SQL> insert /*+ APPEND */ into <table>;

Then no redo will be generated. Is that a correct understanding?

--
Regards,
Greg Rahn
http://structureddata.org
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