RE: compress dbf backup files

From: Mark W. Farnham <>
Date: Mon, 1 Feb 2016 18:08:56 -0500
Message-ID: <024101d15d45$874333f0$95c99bd0$>

A few things:  
  1. Mladen's questions are directly on point.
  2. "They are the only copies of the existing readonly dbffiles."
    1. Farnham's Law: "Don't trust your career to a single piece of spinning rust or ribbon rust." (Ribbon rust is a tape. This should probably be updated to "single piece of media" but spinning rust and ribbon rust are helpful images to remember how fragile your career might be if you violate Farnham's Law.)
    2. I hope you mount these for a few minutes and read something from them every time you patch anything in the entire stack. Otherwise they might become the only copies of these files that run on a machine/operating system you no longer have in close enough detail. (Did I ever tell you the one about 9-track tapes and the changing hardware specifications over time of maximum drift adjustments where the new "better" tape drive simply could not be adjusted to read *some* of the tapes that had been written on the "gone" drives with a larger than average drift. Sigh. It wasn't funny at the time either..
  3. If space and compression is an issue then I suggest that in addition to possibly reloading and compressing as per the methods Seth mentioned earlier in the thread you use a reasonable protocol for tablespaces that have become read only whether or not you leave them unmounted most of the time. Among the features of such a protocol:
    1. If the tablespace to become unmounted has more than trivial free space, copy everything in the tablespace into something just big enough as compressed as you plan to keep it. Partition exchange methods might be helpful.
    2. Consider using direct load so you don't have any delayed cleanout issues reading things much later.
    3. Consider making the destination a less expensive "class" of storage than your active database files is on.
    4. Make another copy somewhere else that will survive independently of the campus this file is on.

There is probably more.  


From: [] On Behalf Of Mladen Gogala
Sent: Monday, February 01, 2016 4:03 PM
Subject: Re: compress dbf backup files  

On 02/01/2016 12:09 PM, Zelli, Brian wrote:

I have copies of dbf files sitting on a server. Management doesn't want me deleting them. So to garnish space, can I compress these? They are only copies of the existing readonly dbffiles.    


This email message may contain legally privileged and/or confidential information. If you are not the intended recipient(s), or the employee or agent responsible for the delivery of this message to the intended recipient(s), you are hereby notified that any disclosure, copying, distribution, or use of this email message is prohibited. If you have received this message in error, please notify the sender immediately by e-mail and delete this email message from your computer. Thank you.

Hi Brian,
How old are those files? What does your management expect from having them? What is your company's backup strategy? Do you have an enterprise backup suite? How frequently do you take backup and where do you store it? How do you take backups?


Mladen Gogala
Oracle DBA
Tel: (347) 321-1217

-- Received on Tue Feb 02 2016 - 00:08:56 CET

Original text of this message