Basic Doubt About Segment

[badrinathn]

Hi,
I just want to know whether a different segment will be allocated for every object(like table,view, trigger, index)
or it's only the extents which will be created for these.

Please clarify

Badrinath

[nirasha]

From my understanding, tables, indexes etc are types of segments.

Nirasha

[sreddy]

Yes different segment will be allocated for diffrent type of object. BTW, View will not be having any segment as its virtual.

[SANJAY_G]

Segments are assigned to Tables, Indexes, Clusters. There are also rollback and temp segments however views, triggers, sequences will not have any segments assigned to it.

Sanjay

[rohitsn]

In Oracle ,everything is stored in blocks.An extent is a set of contignous blocks allocated for a database object.A segment is a collection of all the extents allocated for a database object.
So when u create any object in Oracle such as a table,index,rollback segment.For each of these a segment is created.
When u create a table,a data segment will be created to store the table data.When u create a index,an index segment will be created to store the index values.When u create a rollback segment ,a rollback segment will be created to store the undo data.
The segment name is the same as the table name or index name.So when u create a table named emp ,an emp segment gets created to store the data of emp table,U can verify it through dba_segments table.
So a segment will contain all the extents which are allocated for a database object.This segments get created through ur storage paremeters of ur table or index or rollback segment
If u have more doubts in this please mail me to rohitsn@hotmail.com

[SIVAKUMARN]

Hi Nihra,

U r Doing great job by providing detailed messages.

keep it up and All the Best.

You can mail me for further correspondence thru
sivakumarnv@yahoo.com

Shiva