RE: Informix versus oracle

Actually, the purpose for archived log mode is more for the purposes of point-in-time recovery, and the ability to perform online backups. If you are not running in archive log mode, then the redo logs get cycled through regardless. If you are running in archive log mode, then the redo logs must get backed up before they can be used again. Generally most people turn this feature on when switching the instance to use archive logs mode - if it is not set to automatically backup up these files, then you must archive them manually - working much the same if you forget to backup logical logs using onbar (which I have seen most often scripted into the alarm program for informix). As I stated originally, I could go more in depth with this subject without having to reference another document, but I am only trying to hit the high level concepts - for more information on Oracle, it should be moved to Oracle's usenet groups. -----Original Message----- From: Mark Townsend [SMTP:markbtownsend@attbi.com] Sent: Sunday, June 08, 2003 5:45 PM To: informix-list@iiug.org Subject: Re: Informix versus oracle Jonathan Leffler wrote: > Dusty Haas wrote: > >> Actually, Oracle has been able to take on-line backups for a long time. >> >> There are a few different methods - > > > > Thanks for the explanation. It's useful, but not quite 100% correct. You need to look at the doc to get a full view - suggest you start with the Backup and Recovery Concepts - http://download-east.oracle.com/docs/cd/B10501_01/server.920/a96519/intr o.htm#BROVW001 Note that you may need a logon to OTN, but it's free, and we won't bite (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. [...] > > > > What is the significance of 'archive log mode'? Does it place > restrictions on what can happen to the database(s) while the system is > in that mode? What restrictions? > Archive log mode means that the current redo logs are being copied to another destination after they are used (after a log switch), so that they can become available for re-use as required.