Powered By Blogger

Sunday 22 April 2012

Difference between VIEW and SYNONYM.


Difference between VIEW and SYNONYM.
                          view
                        synonym
1.   It doesn’t contain data itself.

     2.view occupies no space for data

     3.view has only query


1. It contain data itself.

2.synonym occupy space for data

3.synonym can be used as an alias name for the table name

Difference Between ROWID AND ROWNUM


Difference between ROWID and ROWNUM.
                       Row id
                           RowNum
1.Physical address of the rows.

2.Rowid is permanent
3.Rowid is 16-bit hexadecimal
4.Rowid gives address of rows or records
5. Rowid is automatically generated unique id of a row and it is generated at the time of insertion of row.
6. ROWID is the fastest means of accessing data.
7. They are unique identifiers for the any row in a table.

1. Rownum is the sequential number, allocated to each returned row during query execution.
2. Rownum is temporary.
3.Rownum is numeric
4.Rownum gives count of records
5. Rownum is an dynamic value automatically
retrieved along with select statement output.
6. It represents the sequential order in which Oracle has retrieved the row.

Difference Between TRIGGER AND PROCEDURE


¯  Trigger Vs Procedure
                  Trigger
                   Procedure
1.   Trigger does not accept parameters.

2.   A trigger is executed implicitly by the oracle engine.
1. Procedure accepts the parameters.


2.Procedure is execute explicitly, called by a user

Difference Between FUNCTION AND PROCEDURE


Procedure Vs Function
                    Procedure
                   Function
1. Procedure doesn’t contain return clause in header & executable part.

2. Procedure may be return or may not be return a value.

3. Procedure can’t be called into select statements.

4. Procedure are used to implement business logic.
1. Function contain return clause in header & executable part.

2. Function always returns a value.


3. Function can be called into select statement.

4. Function are used for numeric calculation.