learn-oracle


Learn Oracle



PREVIOUS CHAPTER | NEXT CHAPTER

I have created this learn oracle "The step 10 process" Oracle Tutorial to help Database aspirants to accomplish their dream of working as Oracle Database administrator. I have tried to keep it simple and User friendly. Use NEXT and PREVIOUS Button to navaigate away and to a chapter. Since i myself had been a Database adminstrator trainer and has got real life experience of working as a Oracle DBA, I would welcome any sort of queries and doubts or modifications to webmaster@oracleonline.info.

Step 6 - using Datafiles

Learn Oracle - Datafiles

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

Datafiles can be broken down into the following components:

Segments and extents

A segment contains a specific type of database object. For example, tables are stored in data segments, and indexes are stored in index segments.

An extent is a contiguous set of data blocks (defined next) within a segment.



Oracle initially allocates an extent of a specified size for a segment, but if that extent fills, then more extents can be allocated

Data block

Data blocks, also called database blocks, are the smallest unit of I/O to database storage. An extent consists of several contiguous data blocks. The default database block size is specified by a Oracle DBA at database creation or defaulted by Oracle. After the database has been created, it is not possible to change the default block size without re-creating the database. However, it is possible to create tablespace with a block size different than the default block size.

USERS

This tablespace is used to store permanent user objects and data.

Like the TEMP tablespace, every database should have a tablespace for permanent user data that is assigned to users. Otherwise, their objects will be created in the SYSTEM tablespace, and this is not good practice.

In the preconfigured database, USERS is assigned the default tablespace, and space for all objects created by non-system users comes from this tablespace. For system users, the default permanent tablespace remains SYSTEM.

Click Datafiles. Your database datafiles are displayed. Select a datafile and click View to see more attributes for the datafile, or select a tablespace link to see the attributes of the owning tablespace.
Oracle Tutorial - BLOGS
PREVIOUS CHAPTER | NEXT CHAPTER

STEP 6 - Next Topics
This Step discusses management of the database's storage structure. Click on Oracle tuorial links below:
The Control FileControl file
Redo Log FilesRedo log file
Archive Log FilesArchive log file
TablespacesTablespaces
DatafilesDatafiles
Initialization Parameter File
Password File
Backup Files
Viewing Tablespaces in your Database
Creating a tablespace
Modifying a Tablespace
Dropping a Tablespace
Managing Undo for Your Database
ORACLE DBA - DISCUSSION FORUMS
Oracle Database - PODCASTS
More Tutorials on Oracle dba ...



Liked it ? Want to share it ? Social Bookmarking
Add to: Mr. Wong Add to: BoniTrust Add to: Newsider Add to: Digg Add to: Del.icio.us Add to: Reddit Add to: Jumptags Add to: StumbleUpon Add to: Slashdot Add to: Netscape Add to: Furl Add to: Yahoo Add to: Spurl Add to: Google Add to: Blinklist Add to: Technorati Add to: Newsvine Information


Source : Oracle Documentation | Oracle DBA

Want to share or request Oracle Tutorial articles to become a Oracle DBA. Direct your requests to webmaster@oracleonline.info