| written 8.9 years ago by | modified 3.8 years ago by |
Mumbai University > Information Technology > Sem 5 > Advanced Database Management System
Marks: 10M
Year: May 2016
| written 8.9 years ago by | modified 3.8 years ago by |
Mumbai University > Information Technology > Sem 5 > Advanced Database Management System
Marks: 10M
Year: May 2016
| written 8.9 years ago by |
Many case tools are available for data modelling.
EAST tools are used for creating the logical and the physical schema for particular database management systems (DBMS).
| OLTP (OPERATIONAL DATABASE MODELLING) | OLAP (DATA WAREHOUSE MOELLING) |
|---|---|
| OLTP systems focus is on individual database transaction. | Data warehouse focus is on how executive users like managers view business. |
| An OLTP system maintains micro-level transactions. | Data warehouse shows business trends and operations. |
| Data at detail level necessary to run the business. | Information concentrates on business processes. |
| Suitable only for transaction level. | Business measures the process, can be calculated. |
| Data consistency, non-redundancy and efficient storage of data. | To study measures of many business dimensions. |
| It contains current data. | It contains current as well as historic data. |
| It has more no. of users. | It has less no. of users. |
| Access frequency of data is high. | Access frequency of data is low. |
| It is called as OLTP assuming that operation system. | It is called OLAP assuming that information system. |
| ER model is used. | Dimensional modelling is used. |
| It provides transaction throughput. | It provides query throughput. |
| Allows read/write operations. | Only reads and rarely writes. |
| Provides high performance. | Provides high flexibility. |
Product :-
Create table product (prod_id number(2) primary key, prod_name varchar2(20), prod_desc varchar2(20), prod_value number(3)) ;
Time:-
Create table time (Time_id number(2) primary key, Day number(2), Quarter number(1); Year number(4));
Location:-
Create table Location (Loc_id number(2) primary key, pin_code number(3), city varchar2(20), state varchar2(20));
Sales:-
Create table sales (sales man_id number(2) references department (salesman_id),prod_id number (2) references product(prod_id), time number (2) references time(time_id), loc_id number(2) references.
Location (loc_id), quantity number(3), unit_prize number(7,2)
Advantages of star schema.
Disadvantages