Re: Moving datafiles, freeing space

From: Chuck <chuckh_nospam_at_softhome.net>
Date: 6 Aug 2004 14:30:31 GMT
Message-ID: <Xns953D6AE63E2EAchuckhnospamsofthome@130.133.1.4>

joel-garry_at_home.com (Joel Garry) wrote in news:91884734.0408050948.6c227a2_at_posting.google.com:

> Chuck <chuckh_nospam_at_softhome.net> wrote in message

>> One other thing I want to try is to copy the file instead of moving
>> it, then cat /dev/null over top of the original before rm'ing it. Not
>> sure if this will prove it's a unix problem or not but if it
>> consistently releases the space who cares. That's the real objective.

>
> I started to type in a suggestion like this, then decided not to
> because I think mv/cp are actually quite vendor-dependent, going back
> to the days when you had to worry about which filesystem things were
> on. It's been quite a while since AIX for me.

FYI the cat /dev/null thing worked great. Released the space immediately. I'm still not sure whether checkpointing the database accomplished the same thing by beating the RDBMS over the head, or if it was just coincidence. My guess is it kicked something within oracle to release the space.

My new procedure for relocating a datafile on unix will be to copy instead of moving it, and cat /dev/null the original file when done. On windows I'll have to keep some zero length file around for the same purpose.

BTW I still have to worry about which filesystems things are on. Not so much for performance as in the old days but for space management.

-- 
Chuck
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Received on Fri Aug 06 2004 - 09:30:31 CDT