A Data Warehouse system gives its users a common data model for all the data of interest without bothering about the source of the data. This makes it easier for users to report and analyze the information for sales invoices, general ledger charges and other tasks. A data warehouse can also work in conjunction, which enhances the value of operational business applications and customer relationship management systems.
Designing and implementing a warehouse in not an easy thing as lot of focus and importance is attached to it. If you are the designer of the data warehousing system, you could be asked to take all the enterprise data and make a data warehouse where the management would get all the answers to their queries. This is something tough but equally exciting and visible.
The two main parts of designing a data warehouse is how to start it and where to start. The toughest part is to bring down the scope of the vast project to something smaller, manageable yet scalable. In recent time, the trend of building data marts before making the real data warehouse is popular amongst developers. We always prefer to have something smaller to manage things before proceeding to the real warehouse.
Here are the nine methods you can follow for designing a flawless data warehouse:
o Choose the subject matter on which the data warehouse has to be designed.
o Decide what all would the fact table represent.
o Identify the dimensions of the design and confirm them.
o Choose the facts.
o Do pre-calculations and store them in the fact table.
o Properly define definitions and tables.
o Find the duration of the database and the periodicity of up gradation.
o Slowly track the changes in dimension.
o Decide the query priorities and their modes.
The last step is to implement a simple data warehouse or a data mart. Always remember that your approach should be from simpler to complex. Initially only a few data marts are identified, designed and implemented that will gradually lead to the designing of a complete data warehousing system.
There are a few technological issues that one should consider while designing and implementing a data warehouse:
o Hardware platforms for data warehousing systems.
o System management and operating system platforms.
o DBMS for supporting data warehouse.
o Software tools for building, operating and using the warehouse.
o Communication and network infrastructure.
Financial consideration should also be given because the implementation of a data warehousing system is very time consuming and expensive. It requires heavy involvement from a lot of resources in your company and will require manipulation of data in order to get the correct formatting required to be effective. Many people fail to calculate the full cost of a data warehousing implementation which causes the company to far exceed their budget while the project is only half complete. In order to effectively estimate costs for the implementation, people must also be calculated along with technology and hardware. Without including employee time, you will grossly underestimate the costs.