RE: question about progress of shrink operation

From: Mark W. Farnham <mwf_at_rsiz.com>
Date: Sat, 27 Jan 2024 15:06:36 -0500
Message-ID: <479701da515c$55b30e50$01192af0$_at_rsiz.com>



+42.  

Likewise if conditions are correct for you to copy to a new location to effectively “shrink” rather than making shrink work, a reasonable amount of work should go into the optimization of the details about your LOB storage in the destination. The storage choices should not affect the ability to copy from your current source to a new destination, but they may make a significant change in the storage footprint in the destination.  

IF memory serves and IF a substantial number of your lobs should no longer be logically changed, things effectively like pctfree for “regular” block storage might be set very small for the copy in of those now unmutable lobs, and then be set optimally for change of your still mutable lobs before they are copied in. Don’t trust my memory on this, especially for more recent releases. A change from basicfile in the original to securefile in the destination may well be more important than anything else if the current lobs are basicfile.  

Notice in particular than zero of what I have written changes or challenges what JL has written about getting shrink to work at all.  

mwf  

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Jonathan Lewis Sent: Saturday, January 27, 2024 1:43 PM To: ORACLE-L (oracle-l_at_freelists.org) Subject: Re: question about progress of shrink operation  

A question I forgot to ask - are your LOBs securefile or basicfile, and what are your logging, caching, and "storage in row" settings. Again, it might make a difference.

Regards

Jonathan Lewis    

On Fri, 26 Jan 2024 at 08:42, Laurentiu Oprea <laurentiu.oprea06_at_gmail.com> wrote:

Dear all,  

What will happen with progress of a shrink operation of a CLOB if it fails due to various reasons like for example undo space. Will it be all lost or partially lost or no lost progress?  

THank you.

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Received on Sat Jan 27 2024 - 21:06:36 CET

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