Types of Inventory Models
1.
Periodic snapshot
2.
Inventory Transactions
3.
Inventory Accumulating Snapshots
Periodic Snapshot
This type of model takes the snapshot of data at regular
intervals of time and stores it in DWH. The grain in such a fact table would be
date at which the snap shot is taken. For example in Banking business it is
very important to understand what is the Gross Loan amount, Net Loan amount,
gross receivable, net receivable, gross delinquent amount at the end of each
month or week. Thus to capture the complete business snapshot, snapshot is taken at the
end of every regular interval. This enables the analysts
to compare the business situation and performance let’s say business in March 2011 with
the business in April 2011 or with business in March 2012.
Since the date when the snapshot is taken holds the highest
importance it serves as the key in the fact table
Inventory Transactions
In this type of model every single transaction is recorded
and thus it increases the granularity. The grain in such a schema is the transaction. Thus even if the transaction fact table is
simple in nature it still contains a lot of information.
Inventory
Accumulating Snapshot
This kind of model serves best when a process, which is
modelled, has a definite beginning some definite milestones and a definite end.
One row is generated and each cell of that row is populated as and when the
milestone is achieved.
For example in a Loan processing system, when the loan is
approved a row is generated in the fact table and then here are multiple steps
in a pipeline till the time final disbursement is made. The row would contain
the loan approval date, the document submission date, the document send to back
office date, the document verification date and loan disbursement date. Each
and every time when the milestone is achieved the cell is updated. This process
is very useful to understand the pipeline and visualize the complete loan
disbursement process in one go.
Comparison
References
2.
Ralph Kimball, Margy Ross The data Warehouse
Toolkit 3.0
No comments:
Post a Comment