Databases Reference
In-Depth Information
In step 4, we query the
V$LOG
dynamic performance view, in which we can find more details
regarding redo logs, as in the following screenshot:
In the excerpt shown in the previous screenshot, you can see the redo log group (GROUP#),
the sequence number (the first SCN, System Change Number) in each group (SEQUENCE#),
the size of each group's members (BYTES), the status (STATUS), and whether the log is
archived or not (ARC).
In step 5, finally, we query the
V$LOG_HISTORY
dynamic performance view, obtaining a row
for each log switch. This view is useful to verify the log switch frequency, and indicates the first
and last change numbers in the log file.
This information is stored in the control file; the
MAXLOGHISTORY
clause, specified when the
control file was created, indicates the length of time for which the information is retained in
the control file itself.
In the following screenshot, you can see an excerpt of the results obtained by the query
executed in step 5:
