Re: Logs filling up?

Guy Pardoe (Info_at_PardoeOnline.com) wrote:
: In Oracle, I assume there are transaction logs and I also assume I
: must clear them or someday the database will choke on me. I have been

Not really, no.

Oracle has a series of redo log files which are used in rotation. When one redo log is full then Oracle will switch to the next. The redo logs hold the changes to the database files. They are used, amongst other tings, for instance recovery and "roll forward" if the database crashes.

If you turn oracle archive logging on then on a logfile switch a COPY of the log file is written to another area of the disk. This is very very beneficial for database recovery because you use these to "replay" changes to the database if you ever have to restore to an earlier backup. They can also be used for building a warm standby database.

Of course, these archived files can/will take up disk space and will eventually require deleting, but this is now outside of the database and can be done with normal OS level tools. Archiving logging is not a default configuration (you have to enable it specifically).

As such, you can see that oracle doesn't keep an ever-growing transaction history, and so you don't have to worry about trimming it down on a regular basis.

--

rgds
Stephen Received on Sun May 30 1999 - 08:30:11 CDT