I don't currently have an AIX box to test, but I do have Solaris 10 running, and can show: /export/home/oracle/joework> ls -l atg-smowner.dmp -rw-r----- 1 oracle dba 193003520 Sep 12 16:32 atg-smowner.dmp /export/home/oracle/joework> compress atg-smowner.dmp /export/home/oracle/joework> ls -l atg-smowner.dmp* -rw-r----- 1 oracle dba 89629298 Sep 12 16:32 atg-smowner.dmp.Z /export/home/oracle/joework> uncompress atg-smowner.dmp.Z /export/home/oracle/joework> ls -l atg-smowner.dmp* -rw-r----- 1 oracle dba 193003520 Sep 12 16:32 atg-smowner.dmp /export/home/oracle/joework> gzip atg-smowner.dmp /export/home/oracle/joework> ls -l atg-smowner.dmp* -rw-r----- 1 oracle dba 70873960 Sep 12 16:32 atg-smowner.dmp.gz A 193MB file compresses to ~90MB, and gzips to ~71MB. Almost no difference in processing time (though I didn't document that in this quick-n-dirty demo). I've experienced the same results (gzip output roughly 30% smaller than compress) on many UNIX boxes at many places over many years. But, then again, "your mileage may vary" Joe Cooper Senior Oracle DBA Department of Veterans Affairs Austin, TX Joe Smith <joe_dba@xxxxxxxxxxx> wrote: .hmmessage P { margin:0px; padding:0px } body.hmmessage { FONT-SIZE: 10pt; FONT-FAMILY:Tahoma } Which is better to use gzip or compress? All of my work is done on AIX 5L 64bit server. I am doing cold backups of databases where I tar and then compress the resulting file. I have always used compress, but I read that gzip gives better compression. Any thoughts will be appreciated. --------------------------------- Shed those extra pounds with MSN and The Biggest Loser! Learn more. --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.