What is control file multiplexing?

Multiplexing is the process of mintaining a copy of same control files on different disk drivers (and idealy on different controllers). To multiplex your control files, we copy the control file to multiple locations and change the CONTROL_FILES parameter in the text based initialization file init.

Why we do control file multiplexing?

As a DBA, it’s your responsibility to multiplex control files to protect your organization in case of possible data loss due to media failure or control file corruption. Creating a copy of controlfile in a new location with a new name .

What are the steps to multiplex control file using Pfile and Spfile?

1. SPFILE

1. Step1. 1: Validate existing control files.
2. Step 1.2: Add new control file to SPFILE.
3. Step 1.3: Stop database.
4. Step 1.4: Copy the control file to a new location.
5. Step 1.5: Start the database in normal mode.
6. Step 1.6: Validate control files.
7. Step2.
8. Step 2.2: Create PFILE using SPFILE.

Where are Oracle control files located?

ORACLE_BASE\oradata \DB_NAME directory
The preconfigured database contains two control files located in the ORACLE_BASE\oradata \DB_NAME directory. Oracle recommends that you keep at least two control files (on separate physical drives) for each database, and set the CONTROL_FILES initialization parameter to list each control file.

How do I read a control file?

Answer: To see the controlfile contents, use these steps: SQL> alter database backup controlfile to trace; We can now view the controlfile contents (as a “create database” statement) by looking for the latest file in the user_dump_dest directory.

What is a control file?

A control file is a small binary file that records the physical structure of the database and includes: The database name. Names and locations of associated datafiles and online redo log files. The current log sequence number. Checkpoint information.

How do you create a control file?

Complete the following steps to create a new control file.

1. Make a list of all datafiles and redo log files of the database.
2. Shut down the database.
3. Back up all datafiles and redo log files of the database.
4. Start up a new instance, but do not mount or open the database: STARTUP NOMOUNT.

What is Oracle control file?

Every Oracle database has a control file. A control file is a small binary file that records the physical structure of the database and includes: The database name. Names and locations of associated datafiles and online redo log files. The timestamp of the database creation.

What is redo log file in Oracle?

What Is the Redo Log? The most crucial structure for recovery operations is the redo log, which consists of two or more preallocated files that store all changes made to the database as they occur. Every instance of an Oracle Database has an associated redo log to protect the database in case of an instance failure.

Is more recent than control file?

file is more recent than controlfile – old controlfile This ORA-01207 error is related to the control file change sequence number in the datafile is greater than the number in the control file. This implies that the wrong control file is being used.

Can we edit control file?

Similarly, you rename an existing control file by copying the file to its new name or location, and changing the file name in the control file list. In both cases, to guarantee that control files do not change during the procedure, shut down the database before copying the control file.

What does a control file contain?

A control file is a small binary file that records the physical structure of the database and includes: The database name. Names and locations of associated datafiles and online redo log files. The timestamp of the database creation.

Is there a way to multiplex Oracle control files?

Answer: There are two ways to multiplex the oracle control files, init.ora and spfile. Multiplexing Control Files using the init.ora file. Multiplexing is the process of mintaining a copy of same control files on different disk drivers (and idealy on different controllers).

How big is the control file for Oracle?

SQL> startup ORACLE instance started. Total System Global Area 755769344 bytes Fixed Size 2217184 bytes Variable Size 478153504 bytes Database Buffers 272629760 bytes Redo Buffers 2768896 bytes Database mounted. Database opened.

What does it mean to Multiplex Control Files?

Multiplexing is the process of mintaining a copy of same control files on different disk drivers (and idealy on different controllers). To multiplex your control files, we copy the control file to multiple locations and change the CONTROL_FILES parameter in the text based initialization file init.ora to include all control files names.

How to Multiplex Control Files with Donald Burleson?

1. Alter System set CONTROL_FILES = ‘u02/oradata/ord/control01.ctl’, 2. Shut down the instance 3. Copy the control file to more locations using operating system command. The best on site ” Oracle training classes ” are just a phone call away! You can get personalized Oracle training by Donald Burleson, right at your shop!