What is the use of control file in Oracle database?

What is the use of control file in Oracle database?

A control file is a small binary file that is part of an Oracle database. The control file is used to keep track of the database’s status and physical structure. Every Oracle Database must have at least one control file. However, it is recommended to create more than one, up to a maximum of 8.

Where are Oracle control files located?

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.

What is the importance of a control file?

A control file tracks the physical components of the database. It is the root file that the database uses to find all the other files used by the database. Because of the importance of the control file, Oracle recommends that the control file be multiplexed, or have multiple identical copies.

How do I create a control file in Oracle?

To create a control file, you must have the SYSDBA system privilege. The database must not be mounted by any instance. After successfully creating the control file, Oracle mounts the database in the mode specified by the CLUSTER_DATABASE parameter. The DBA must then perform media recovery before opening the database.

Can we read control file in Oracle?

Once the disk drive is repaired, the damaged control file can be restored using the intact copy of the control file from the other disk and the instance can be restarted. The first file listed in the CONTROL_FILES parameter is the only file read by the Oracle database server during database operation.

What is CTL file?

what is a . ctl file? The Microsoft Visual Studio 2010 software uses files appended with the . ctl format as developer files. These are stored in the CTL format that was created by Microsoft, and these CTL developer files are also called Visual Basic UserControl Object files.

What is a tablespace in Oracle?

A tablespace in an Oracle database consists of one or more physical datafiles. A datafile can be associated with only one tablespace and only one database. Oracle creates a datafile for a tablespace by allocating the specified amount of disk space plus the overhead required for the file header.

How do you create a control file?

Steps for Creating New Control Files

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.

How do I view a control file?

How to Find Control File in Oracle

1. The database name.
2. The timestamp of database creation.
3. The names and locations of associated data files and redo log files.
4. Tablespace information.
5. Data file offline ranges.
6. The log history.
7. Archived log information.
8. Backup set and backup piece information.

How do I manually create a Controlfile?

1 Answer

1. Shut down the database.
2. Copy an existing control file to a new location, using operating system commands.
3. Edit the CONTROL_FILES parameter in the database initialization parameter file to add the new control file name, or to change the existing control file name.
4. Restart the database.

What is Lgwr process in Oracle?

Log Writer process (LGWR) is a background Process that writes redo log entries sequentially into redo log file. Redo log entries are generated in the redo log buffer of the SGA. If the database has a multiplexed redo log, then LGWR writes the same redo log entries to all of the members of a redo log file group.

How do I read a .CTL file?

4 Easy Ways to Open CTL Files

1. Use Another Program. If you can’t view the CTL file by double-clicking it, try opening it in a different program.
2. Get a Clue From the File Type. One file extension can be used for multiple types of files.
3. Contact a Developer.
4. Get a Universal File Viewer.
5. Recommended Download.

What information is stored in an Oracle control file?

Every Oracle Database has a control file, which is a small binary file that records the physical structure of the database. The control file includes: The timestamp of the database creation The control file must be available for writing by the Oracle Database server whenever the database is open.

What does a control file contain?

Answer: The Control File of the database is a binary file that contains a great deal of database information. The control file contains the database name, data about the database log files. Oracle cannot function without valid control files.

How do I create an Oracle Database?

Steps for Creating an Oracle Database Step 1: Back up any existing databases. Step 2: Create parameter files. Step 3: Edit new parameter files. Step 4: Check the instance identifier for your system. Step 5: Start Enterprise Manager and connect to Oracle as an administrator. Step 6: Start an instance. Step 7: Create the database.

What is the file extension of an Oracle Database?

The file extension is the part after the period in the filename. Many DBAs typically use the “.dbf” file extension for Oracle datafiles to signify that this datafile is a database file, or dbf. But you can use anything you want.

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