Question: How Do I Know If My Datafile Is Offline Or Online?

Which tablespace Cannot be taken offline?

You cannot take the following tablespaces offline: SYSTEM.

The undo tablespace.

Temporary tablespaces..

What is different about V Datafile and Dba_data_files?

This question is Answered . Can someone please explain to me what is the difference between dba_data_files and v$datafile views? Both have the same number of records, the only differences I see is that v$datafile view has more fields and some fields are different (v$datafile does not have user-bytes fiels.

How do I change a tablespace from read only to online?

Use the READ ONLY clause in the ALTER TABLESPACE statement to change a tablespace to read-only. You must have the ALTER TABLESPACE or MANAGE TABLESPACE system privilege. Before you can make a tablespace read-only, the following conditions must be met. The tablespace must be online.

What is data file in Oracle?

Data files are the operating system files that store the data within the database. The data is written to these files in an Oracle proprietary format that cannot be read by other programs. Tempfiles are a special class of data files that are associated only with temporary tablespaces.

How do you put a tablespace in read only mode?

Creating a Read-Only Tablespace on a WORM DeviceCreate a writable tablespace on another device. Create the objects that belong in the tablespace and insert your data.Alter the tablespace to make it read-only.Copy the datafiles of the tablespace onto the WORM device. Use operating system commands to copy the files.

What is Dba_data_files?

4.158 DBA_DATA_FILES DBA_DATA_FILES describes database files. … The actual size of the file minus the USER_BYTES value is used to store file related metadata.

How do I make a table read only in Oracle?

Oracle 11g allows tables to be marked as read-only using the ALTER TABLE command. alter table table_name read only; alter table table_name read write; The following script creates a table, inserts a row, then sets the table to read-only.

How would you drop a tablespace if the tablespace were not empty?

First, specify the name of the tablespace that you want to drop after the DROP TABLESPACE keywords. Second, use the INCLUDE CONTENTS to delete all contents of the tablespace. If the tablespace has any objects, you must use this option to remove the tablespace.

Is it possible to change the status of system tablespace from online to offline explain?

You can take an online tablespace offline so that it is temporarily unavailable for general use. The rest of the database remains open and available for users to access data. Conversely, you can bring an offline tablespace online to make the schema objects within the tablespace available to database users.

Where is Oracle data file located?

DB_CREATE_FILE_DEST specifies the default location for Oracle-managed datafiles (see its entry in the Database Reference). To access the v$parameter view a user needs at least the SELECT_CATALOG_ROLE role. It works for ME because all our datafiles are installed in a the same directory.

Can we take system tablespace offline?

You cannot make the SYSTEM tablespace read only or temporary and you cannot take it offline.

How can I tell if tablespace is read only?

Once a tablespace is made offline, it is simply unavailable to the database. Hence, no information is present in the v$datafile_header. 2. When a tablespace is made read-only, the checkpoint_change# (Datafile checkpoint change#)visible in v$datafile_header freezes.

What is .DBF file in Oracle?

Datafiles are physical files of the operating system that store the data of all logical structures in the database. They must be explicitly created for each tablespace. Oracle assigns each datafile two associated file numbers, an absolute file number and a relative file number, that are used to uniquely identify it.

How is data stored in Oracle Database?

Oracle Database allocates logical space for all data in the database. The logical units of database space allocation are data blocks, extents, segments, and tablespaces. At a physical level, the data is stored in data files on disk (see Chapter 11, “Physical Storage Structures”).

What is Maxbytes in Dba_data_files?

When we query the DBA_DATA_FILES table (for scripting), we need to take extra care while getting data from MAXBYTES column. Notice the MAXBYTES value is 0 for the last 2 datafiles. The reason for this is because during the creation of the datafile, the MAXSIZE was not specified.

How do I resize a datafile?

Extending a tablespace by resizing the datafile Another way to extend a tablespace is to resize the data file by using the the ALTER DATABASE RESIZE DATAFILE statement: ALTER DATABASE DATAFILE ‘path_to_datafile’ RESIZE size; Consider the following example.