Re: Informix versus oracle

I well remember trying to restore an EBU backup. After two weeks of going around with tech support and finally determining that the fellow who had written the process had left the company we gave up and went back to initial load. Good thing we weren't live yet - we wound up going for a cold disk backup in the end - safer. cheers j. ----- Original Message ----- From: "Dusty Haas" <dhaas70@qwest.net> To: <informix-list@iiug.org> Cc: "'rkusenet'" <rkusenet@sympatico.ca> Sent: Saturday, June 07, 2003 7:27 PM Subject: RE: Informix versus oracle > Actually, Oracle has been able to take on-line backups for a long time. > > There are a few different methods - > > In each case you can substitute the word dbspace for tablespace, and > datafile for chunk for ease of understanding between Informix and Oracle. > > First it can be scripted using key statements such as "alter tablespace > <tablespace name> begin backup;" > This will then allow you to backup each datafile - without going in depth > too much. You must be running in "archive log mode" for this to work > though or you would get an error saying that the instance must be in > archive log mode. This has been available since version 7.3 - possibly > earlier - I cannot remember when that started. > > The other option is to use EBU (emergency backup utility) with version 7.3 > and older, or RMAN (recovery Manager) as of 8.0 and higher - this would be > closer to the same kind of tasks that onbar or ontape use. Again, as above > you need to be in archive log mode or it will complain (note that in a cold > backup situation this is not the case as the instance will be down, and > therefore backups would be considered consistent, but the instance would be > unavailable during the time) > > One of the other major differences is that the logical logs (in Oracle's > case they are called either redo logs/archive logs for simplicity sake - > there is a small difference in how they are worked as well) - anyway the > logical logs are stored in chunks in Informix - in Oracle they are written > out to the OS and then backed up from there (though they can be configured > to write to multiple locations such as both tape and disk and remote > network server). > > So, to answer the question without going in depth is that Oracle has been > able to do this for some time. Unfortunately, it has been my experience > that Informix's backup is much more efficient since it does not need to be > in any special mode essentially, and no extensive scripts are needed to > issue a simple ontape/onbar command (I have not delved in to onarchive, so > I cannot site anything there) > > Also note that I believe recovery is also easier with Informix - again due > to the lack of need for any complex scripts to do a task. > > Hope this helps explain some differences without going to far in depth into > either engine > > -----Original Message----- > From: rkusenet [SMTP:rkusenet@sympatico.ca] > Sent: Saturday, June 07, 2003 7:33 AM > To: informix-list@iiug.org > Subject: Re: Informix versus oracle > > > "Andy Kent" <andykent@cix.co.uk> wrote > > > Can't remember whether Oracle allows you do do backups with users all > > still fully on-line but I think Informix is / was several years ahead > > on that one. > > Is this true??? Oracle can't support on-line backup!!!! > Sounds ridiculous to me. The problem is, in this newsgroup, lot of > anti oracle claims have to be taken with a handful of the needful. > > > rk- > > > >