I know that i can create a table without a primary key.But
is there any significance for that table???? while creating
an application.
Answer Posted / amit
Definitely yes.....While creating a Data Warehouse
application,we need fact tables to be created from various
dimension tables and the fact table load type is always
INSERT not INSERT/UPDATE.Just think of a real world example
where the need is to populate all the daily transactional
data to a Data Warehouse for analytical purpose such as
creating reports and all.Suppose the DW is loaded two times
a day.In the first load,whatever the data present in the
Transactional Database is loaded into the DW.Before the
second load there might be some sort of updation made to
some of the records,so those records need to be inserted
into the DW again in the second load.If there would be
primary key in the fact table(i,e;DW),it will raise an error
(unique constraint violated.....).So,fact tables should not
contain any primary key.
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
Explain a synonym?
How to experiment a data lock in oracle?
What is raw datatype?
How many types of table in Oracle?
How do I manually uninstall oracle client?
What is archive log in Oracle?
What do database buffers contain?
What exactly do quotation marks around the table name do?
What is blob data type in oracle?
What is an oracle cursor variable?
Explain an integrity constrains?
What is oracle used for?
Explain overloading. Can functions be overloaded?
What is proxy method?
Point out the difference between user tables and data dictionary?