[Translated from mos] Method of rebuilding control file, mos Reconstruction

[Translated from mos] Method of rebuilding control file, mos Reconstruction

Reconstruction of Control Files

Reference Original:
How to Recreate a Controlfile (Doc ID 735106.1)

Applicable:
Oracle Database-Enterprise Edition-Version 9.0.1.0 and later
Information in this document applies to any platform.

Solution:

Warning:
You should recreate your control file only in the following scenarios

1. All the current control files, copies, have been lost or damaged)
2. You are restore a backup. In this backup, the control file is damaged or lost (missing)
3. You need to change a hard limit database parameter in the control file)
4. If you are moving your database to a server and files are located in different locations.
5. oracle technical support personnel suggest you recreate the control file.

First, create a new controlfile in an existing db (and the db is in the mount or open state ).

First, an ascii dump file of the control file must be generated.
SQL> alter database backup controlfile to trace;

The trace file is generated in the udump directory:
SQL> show parameter user_dump_dest

NAME TYPE VALUE
--------------------------------------------------------------------
User_dump_dest string/oracle/product/11.1.0/db_1/diag/rdbms/V11/trace

To the/oracle/product/11.1.0/db_1/diag/rdbms/V11/trace directory, sort by Time:
% Cd/oracle/product/11.1.0/db_1/diag/rdbms/V11/trace
% Ls-ltr

Once the file is located, the file is displayed as follows in the general trace file:
Trace file/oracle/product/11.1.0/db_1/diag/rdbms/V11/trace/V11_ora_31225.trc
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0-Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
ORACLE_HOME =/oracle/product/11.1.0/db_1

You are interested in the section that includes the control file creation script.
Modify the trace file and use the modified script to create a control file.

Create controlfile reuse database "V11" NORESETLOGS ARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
# MAXLOGHISTORY 292
LOGFILE
GROUP 1'/oradata/V11/redo01.log 'SIZE 50 M,
GROUP 2'/oradata/V11/redo02.log 'SIZE 50 M,
GROUP 3 '/oradata/V11/redo03.log' SIZE 50 M
DATAFILE
'/Oradata/V11/system01.dbf ',
'/Oradata/V11/sysaux01.dbf ',
'/Oradata/V11/undotbs01.dbf ',
'/Oradata/V11/user01.dbf'
Character set WE8MSWIN1252
;

---> Note: character set WE8MSWIN1252 can be obtained from alert_sid.log.

Alter tablespace TEMP_TEST add tempfile '/oradata/V11/temp01.dbf' reuse;

Delete anything before "create controlfile,
Delete anything after character set. The semicolon must be retained.
In the preceding example, the NORESETLOGS option is selected and the db runs in archivelog mode.
Make sure you use the shutdown immediate option to close the database. Then start to nomount:
SQL> shutdown immediate;
SQL> startup nomount;
SQL> @ control. SQL
 
Note: After recreating the control file, ensure that the temp file already exists:
Alter tablespace temp_ts add tempfile '? /Oradata/V11/temp01.dbf '? Reuse;
Once the control file is created, the db is automatically moved to the mounted state. If you use resetlogs to open the database, make a backup as soon as possible.

 

Case 2: the db cannot reach the mount status.
1. Either the restore control file,
2. Either there is a script to recreate the control file, as shown in the following example:

Create controlfile reuse database "DBNAME" NORESETLOGS ARCHIVELOG
Follow the format listing:
-Location of redo logs.
-Location of datafiles
-Specifying the characterset.

Once you have listed all files correctly you are ready to recreate your controlfile
SQL> startup nomount;
SQL> @ control. SQL

For the control of the mos tube: which one can help analyze the schematic below the border? Explain how the mos controller AOT500 works.

P0.1 is the control, limit 2 outputs the analog, And the op amp is the overvoltage protection comparator. We can guess that limit 2 is related to this function.
Circuit problems:
1. No clearly marked Load
2. the transistor must not all be PNP; otherwise, the record will not be clear.
3. I think the test is correct and can be powered on for verification. It is clear to check the waveform.