What is an Implicit Fact Column?
An Implicit Fact column is used when we have multiple Fact tables and the report is generated only from dimension tables. When a report is generated only from dimension tables(having multiple Facts) then BI Server has multiple join paths available between dimensions and facts.
When a report is generated only from dimensions, it results in error. To overcome this error we create an implicit fact column. This Implicit fact column shows the join path for the BI Server
This can created in the presentation layer in the Admin tool
This can created in the presentation layer in the Admin tool
When you choose columns only from dimensional table,it will not give an error but rather BI server will choose the most economic source of fact table.Most economic fact table is decided based on less number of joins to the fact,less number of records and lastly granularity level respectively in order.
ReplyDeleteImplicit fact is used only to forcefully tell BI server to choose that particular fact even though it may not be the best economic one based on the user requirement.
very true Nazia, error is not generaged, rather the BI server uses the most economic source to fulfill the request. And the most economical source is the one having less number of joins between the fact and the dimensions.
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