Transaction description

Hi,
How to handle the transaction description? Should it be a degenerated dimension?

As a dimension. If this is a free text field then treat the text as the dimension natural key and only store a unique description once. You may consider storing a hash of the text to serve as a alternate non-unique key to serve as an index rather than indexing the entire text field.

ngalemmo wrote:As a dimension. If this is a free text field then treat the text as the dimension natural key and only store a unique description once. You may consider storing a hash of the text to serve as a alternate non-unique key to serve as an index rather than indexing the entire text field.

What to do in case a customer data is updated many times a day and the description is of 2000 characters. Then the dimension will be bulky and cause trouble right? The dimensions are supposed to be thinner than fact.

Exactly the opposite. Thin facts, dimension width is immaterial. A typical star query usully winds up scanning the fact table. Wide fact tables significantly degrade performance.

Still, a transaction data where record is added for each call made by the customer with the remarks column can be considered in dimension?

Not sure what you are asking.

If you don't like the idea of putting the remarks in a dimension table, investigate how your database handles CLOB objects. Some databases allow you to store such columns in a separate area from the main table. In such cases, the overhead inherent in the large column only becomes a factor if the column is used in a query. In such cases, you could store it as a degenerate dimension value in a fact table. Otherwise, store it in its own dimension table. Treat it as a junk dimension and only include rows with unique values.

Actually a customer may call the bank several times a day. In this case, his concerns or opinions can be stored as free text.
Here Customer is a dimension but the text happens to be a transaction. Which means for a customer, there could be multiple texts coming in a day,week or month. Hence storing the text in the dimension could cause a lot of problems. How to handle this?