Guidance:
I. Introduction:
A rollback segment is a part of a database that records information about database changes. Use this information to achieve database read consistency and restoration. If the rollback segment fails, the database cannot be started normally, resulting in database paralysis and the user cannot read or write data. If the rollback segment can be eliminated, the actual data of the user will not be affected. I recently encountered a problem in my practical work: the user deleted the database file rbs01.dbf In the rollback segment tablespace (RBS) by mistake, so that the database could not run properly, next I will exclude the processing steps of this method.
2. steps:
1. First, modify the parameter file init. ora so that the database can be mounted.
There is a system rollback segment in the system tablespace, which is required by the database on the rollback segment. When the database is created for the first time, it is created accordingly, and automatically online as the database is opened. We usually use a public rollback segment instead of a system rollback segment. If a public rollback segment fails, we can replace the system rollback segment temporarily, enables the database to be mounted.
Svrmgrl> shutdown abort
$ VI $ ORACLE_HOME/dbs/init <Sid>. ora
Rollback_segments = (system)
_ Uploupted_rollback_segments = (R01, r02, r03, r04)
Svrmgrl> startup Mount
2. Restore the database and open it again.
Remove the RBS data file rbs01.dbf from the Database Control File.
Svrmgrl> alter database datafile
'##// Rbs01.dbf' offline drop;
Restore the database.
Svrmgrl> recover database using backup controlfile;
At this time, the screen may appear:
Ora_00280 change #### for thread # Is in sequence #
Specify log: [<RET> for suggested | auto | from
Logsource | cancel]
You can find the online log file you need based on the sequence # And enter the log file (including the full path ), when searching online log files, you can use svrmgrl> select * from V $ log. At this time, the database is restored. Then open the database.
Svrmgrl> alter database open resetlogs;
3. recreate a rollback segment
Delete the old rollback segment and the rollback tablespace.
Svrmgrl> alter rollback_segment R01 offline drop;
Svrmgrl> alter rollback_segment r02 offline drop;
Svrmgrl> alter rollback_segment r03 offline drop;
Svrmgrl> alter rollback_segment r04 offline drop;
Svrmgrl> drop tablespace RBS including contents;
Create a new table space and rollback segment.
Svrmgrl> connect internal
Svrmgrl> Create rollback segment Ro tablespace system;
Svrmgrl> alter rollback segment Ro online;
Svrmgrl> Create tablespace RBS datafile
'##// Rbs01.dbf' size ## K;
Svrmgrl> Create rollback segment R01 tablespace RBS;
Svrmgrl> Create rollback segment r02 tablespace RBS;
Svrmgrl> Create rollback segment r03 tablespace RBS;
Svrmgrl> Create rollback segment r04 tablespace RBS;
Svrmgrl> alter rollback segment R01 online;
Svrmgrl> alter rollback segment r02 online;
Svrmgrl> alter rollback segment r03 online;
Svrmgrl> alter rollback segment r04 online;
4. Use the new rollback segment to start the database
Svrmgrl> shutdown abort
$ VI $ ORACLE_HOME/dbs/init <Sid>. ora
Rollback_segments = (R01, r02, r03, r04)
Remove the parameter _ uploupted_rollback_segment.
Svrmgrl> startup normal
Iii. Conclusion:
The Troubleshooting of this fault is performed by the database in archive mode. The author has successfully passed in two System Platforms: HP-UX 10.20 and solaris2.5.
This article is transferred from
Http://oracle.itpub.net/post/20957/229056
