Oracle file types


Oracle file types

<<Previous  Next>>

Explain the types of data files used by the oracle RDBMS.

Oracle file types - Jan 28, 2009 at 18:00 PM by Amit Satpute

Explain the types of data files used by the oracle RDBMS. 

Online redo log files
A control file contains information such as location of redo log files, backup data and redo log information.

The control file is updated to reflect the structure changes every time a datafile or a redo log file is added or dropped from the database. These records are necessary to identify datafiles and redo log files during startup and recovery.

Archive log files
Archived log files are redo logs that Oracle fills with redo entries that are rendered inactive and copied to one or more log archives.

Running the database in ARCHIVELOG mode has the following benefits:

  • Complete recovery of database from instance and media failure.
  • Performing online backups.
  • Transmitting and applying archived redo logs to the standby database.
  • Multiplexed archive logs to avoid single point of failure on the archive logs.
  • More recovery options (tablespace-point-in-time recovery)

Initialization files
Initialization parameter file is a text file in ASCII which contains information needed to initialize a database and instance.

Control files
Control Files contain:

  • The physical structure of a database
  • Database name,
  • Names and locations of associated databases and online redo log files, Timestamp of database creation,
  • Current log sequence number
  • Checkpoint information.

SGA definition files
System Global Area
The System Global Area (SGA) is a shared memory region that contains data and control information for one Oracle instance. When an instance starts, the SGA is allocated by Oracle and is deallocated when the instance shuts down. Every instance has an own SGA.

Online Users share the data in the SGA.

The information stored in the SGA is divided into memory structures like:

  • The database buffers
  • Redo log buffer
  • The shared pool.

Also read
Oracle data types

Explain the differences between char and varchar2 data types, Explain BLOB, CLOB, NCLOB and BFILE, Explain ROWID in oracle, What is a LOB data type?...........

How are extents allocated to a segment?

An extent is stored some specific information. This information is stored using specific number of adjoining data blocks. A collection of extent is called as a segment stored in the same tablespace.............

Oracle Import export

What are the use of Export and Import command?, What are the parameters to be provided while executing Export and Import commands?, What is the difference between the SQL*Loader and IMPORT utilities?..............

Oracle nested table and varrays

A nested table is an unordered set of data elements. These data elements are all of the same datatype. It has a single column whose type is either built in or an object type. It is a table stored within the structure of another table.............

Oracle Security

Explain the security features in Oracle, What are roles? How can we implement roles?, What is user Account in Oracle database?, What is a trace file and how is it created?, What are Tablespace Quota and default tablespace?...........

What is a SQL*Loader Control File?

A SQL*Loader control file contains the following specification: location of the input data file, format of the input date file, target table where the data should be loaded.............

<<Previous  Next>>

Write your comment - Share Knowledge and Experience


Interview questions
Latest MCQs
» General awareness - Banking » ASP.NET » PL/SQL » Mechanical Engineering
» IAS Prelims GS » Java » Programming Language » Electrical Engineering
» English » C++ » Software Engineering » Electronic Engineering
» Quantitative Aptitude » Oracle » English » Finance
Home | About us | Sitemap | Contact us | We are hiring