Modify redo_logfile group membership and size

1.SYS@ORCL > select GROUP#, BYTES/1024/1024 size_M,STATUS,ARCHIVED from v$log

GROUP# SIZE_M STATUS ARC

1 50 INACTIVE YES

2 50 INACTIVE YES

3 50 CURRENT NO

two。 Delete the original log group; (only operate log groups with the status of inactive)

If the log group is current, you need to switch logs first: alter system switch logfile

If active, you can force a checkpoint: alter system checkpoint

SYS@ORCL > alter system switch logfile

System altered.

SYS@ORCL > alter system checkpoint;-- enforce checkpoints

SYS@ORCL > select GROUP#, BYTES/1024/1024 size_M,STATUS,ARCHIVED from v$log

GROUP# SIZE_M STATUS ARC

1 50 INACTIVE YES

2 50 INACTIVE YES

3 50 ACTIVE YES

SYS@ORCL > alter database drop logfile group 1

Database altered.

SYS@ORCL > alter database drop logfile group 2

Database altered.

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After deletion, you also need to specify a directory to delete log files before you can create files. For example, log groups with other names should not have this restriction.

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3. Add 3 log groups with a size of 200m

SYS@ORCL > alter database add logfile group 1'/ u01/app/oracle/oradata/orcl11g/redo01.log'size 200m

Database altered.

SYS@ORCL > alter database add logfile group 2'/ u01/app/oracle/oradata/orcl11g/redo02.log'size 200m

Database altered.

SYS@ORCL > alter database add logfile group 3'/ u01/app/oracle/oradata/orcl11g/redo03.log'size 200m

4. Add a member to a log group

Cd / u01/app/oracle/oradata/orcl11g/

Mkdir redo_bak

SYS@ORCL > alter database add logfile member'/ u01 to group to group 1

Database altered.

SYS@ORCL > alter database add logfile member'/ u01 to group to group 2

Database altered.

SYS@ORCL > alter database add logfile member'/ u01 to group to group 3

Database altered.

5. Delete a log group member

Alter database drop logfile member'/ u01 apprentice.oracle.oradata; orcl11g; redoblembak; redo02qbakandredo02q.log'