| Lesson 10 | Monitoring an open database backup |
| Objective | Explain how to Check the State of an Open Database Backup. |
V$BACKUP and V$DATAFILE views. These views provide information about the backup status of datafiles in the database. Additionally, Recovery Manager (RMAN) can be used to monitor backups, for example, with commands like LIST BACKUP or REPORT SCHEMA, but this lesson focuses on SQL-based monitoring using dynamic performance views.
Connect to the Oracle database using SQL*Plus or any other SQL client with a user that has the necessary privileges (e.g., SYSDBA).
sqlplus / as sysdba
V$BACKUP View:
The V$BACKUP view contains information about the backup status of each datafile. The STATUS column indicates whether a datafile is currently being backed up.
SELECT file#, status, change#, time
FROM v$backup;
file#: The file number of the datafile.status: The backup status of the datafile.
ACTIVE indicates that the datafile is currently being backed up.NOT ACTIVE indicates that the datafile is not being backed up.change#: The system change number (SCN) at which the backup started.time: The time when the backup started (note: the format depends on the database's NLS_DATE_FORMAT setting, and times are typically in the database server's time zone).V$DATAFILE View:
The V$DATAFILE view provides additional information about the datafiles, such as their names and current status.
SELECT file#, name, status
FROM v$datafile;
file#: The file number of the datafile.name: The name of the datafile.status: The current status of the datafile (e.g., ONLINE, OFFLINE, etc.).You can join the V$BACKUP and V$DATAFILE views to get a comprehensive view of the backup status along with the datafile names.
SELECT b.file#, d.name, b.status, b.change#, b.time FROM v$backup b JOIN v$datafile d ON b.file# = d.file#;
ACTIVE status) and which are not (NOT ACTIVE), along with the datafile names and other relevant information.
FILE# NAME STATUS CHANGE# TIME ------ -------------------------------- ---------- -------- --------- 1 /u01/oradata/ORCL/system01.dbf ACTIVE 1234567 2023-10-01 12:00:00 2 /u01/oradata/ORCL/sysaux01.dbf NOT ACTIVE 0 3 /u01/oradata/ORCL/undotbs01.dbf NOT ACTIVE 0 4 /u01/oradata/ORCL/users01.dbf ACTIVE 1234568 2023-10-01 12:05:00
ACTIVE status).NOT ACTIVE status).V$BACKUP view is particularly useful during hot backups (open database backups) to monitor which datafiles are currently in backup mode.V$BACKUP view will not show any active backups since the database is not open.V$SESSION_LONGOPS for long-running backup operations or use RMAN commands to diagnose issues.SQL> desc V$backup Name Null? Type ------------------------------- -------- ---- FILE# NUMBER STATUS VARCHAR2(18) CHANGE# NUMBER TIME DATE
SQL> select * from V$backup;
FILE# STATUS CHANGE# TIME
---------- ------------------ ---------- ---------
1 NOT ACTIVE 0
2 NOT ACTIVE 0
3 NOT ACTIVE 0
4 NOT ACTIVE 0
5 NOT ACTIVE 0
6 NOT ACTIVE 0
7 NOT ACTIVE 0
8 NOT ACTIVE 0
9 NOT ACTIVE 0
10 NOT ACTIVE 0
11 NOT ACTIVE 0
FILE# STATUS CHANGE# TIME
---------- ------------------ ---------- ---------
12 ACTIVE 130521 14-JAN-2020
12 rows selected.
ALTER TABLESPACE BEGIN BACKUP;
SQL> desc V$datafile_header Name Null? Type ------------------------------- -------- ---- FILE# NUMBER STATUS VARCHAR2(7) ERROR VARCHAR2(18) FORMAT NUMBER RECOVER VARCHAR2(3) FUZZY VARCHAR2(3) CREATION_CHANGE# NUMBER CREATION_TIME DATE TABLESPACE_NAME VARCHAR2(30) TS# NUMBER RFILE# NUMBER RESETLOGS_CHANGE# NUMBER RESETLOGS_TIME DATE CHECKPOINT_CHANGE# NUMBER CHECKPOINT_TIME DATE CHECKPOINT_COUNT NUMBER BYTES NUMBER BLOCKS NUMBER
SQL> select name, status, fuzzy from V$datafile_header; NAME STATUS FUZZY --------------------------------------------- ------- ----- /u02/oradata/DVL1/system_DVL1_01.dbf ONLINE /u02/oradata/DVL1/rbs_DVL1_01.dbf ONLINE /u02/oradata/DVL1/temp_DVL1_01.dbf ONLINE /u02/oradata/DVL1/tools_DVL1_01.dbf ONLINE /u02/oradata/DVL1/users_DVL1_01.dbf ONLINE /u02/oradata/DVL1/des_tab_DVL1.dbf ONLINE /u03/oradata/DVL1/des_idx_DVL1.dbf ONLINE /u02/oradata/DVL1/des_rbs_DVL1.dbf ONLINE /u02/oradata/DVL1/synchro_dvl1.dbf ONLINE /u02/oradata/DVL1/olant_dvl1.dbf ONLINE /u02/oradata/DVL1/celeris_dvl1.dbf ONLINE /u02/oradata/DVL1/isd_002_proj_dvl1.dbf ONLINE YES 12 rows selected.
ALTER TABLESPACE BEGIN BACKUP;
ALTER TABLESPACE END BACKUP command is issued.
The next lesson examines the backup implications of logging and nologging modes.