Database Reference
In-Depth Information
Figure 2-1.
Online redo log configuration
The online redo log files aren't intended to be backed up. These files contain only the most recent redo
transaction information generated by the database. When you enable archiving, the archived redo log files are the
mechanism for protecting your database transaction history.
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in an oracle real application Cluster (raC) database, each instance has its own set of online redo logs. this is
known as a
thread
of redo. each raC instance writes to its own online redo logs and generates its own thread of archive
redo log files. additionally, each instance must be able to read any other instance's online redo logs. this is important
because if one instance crashes, then the other surviving instances can initiate instance recovery via reading the crashed
instance's online redo logs.
Note
