What is factless fact table why we need it?
What is factless fact table why we need it?
Factless tables simply mean the key available in the fact that no remedies are available. Factless fact tables are only used to establish relationships between elements of different dimensions. And are also useful for describing events and coverage, meaning tables contain information that nothing has happened.
What is the use of junk dimension?
The junk dimension is a structure that provides a convenient place to store the junk attributes. It is a collection of random transnational codes, flags and/or text attributes that are unrelated to any particular dimension.
What are advantages and disadvantages of fact constellation schema?
Both the star schema have two dimension tables common and hence, forming a fact constellation or galaxy schema. Advantage: Provides a flexible schema. Disadvantage: It is much more complex and hence, hard to implement and maintain.
What are fact tables used for?
A fact table stores quantitative information for analysis and is often denormalized. A fact table works with dimension tables. A fact table holds the data to be analyzed, and a dimension table stores data about the ways in which the data in the fact table can be analyzed.
What is a factless fact schema?
A factless fact table is a fact table that does not have any measures. It is essentially an intersection of dimensions (it contains nothing but dimensional keys). There are two types of factless tables: One is for capturing an event, and one is for describing conditions.
What is the meaning of Factless?
Lacking facts; inaccurate or fictional
factless (comparative more factless, superlative most factless) Lacking facts; inaccurate or fictional.
What is a factless fact?
A factless fact table is a fact table that does not have any measures, i.e. any numeric fields that can be aggregated. For example, if you are modelling product sales, you can have a Sales fact table that will contain the dimension keys and, for example, the “amount” value/measure, to record the amount sold.
What are the properties of fact constellation schema?
Fact Constellation Schema describes a logical structure of data warehouse or data mart. Fact Constellation Schema can design with a collection of de-normalized FACT, Shared, and Conformed Dimension tables. Fact Constellation Schema is a sophisticated database design that is difficult to summarize information.
What are attributes of fact tables?
Fact Table vs Dimension Table Comparison Table
| Characteristics | Fact Table | Dimension Table |
|---|---|---|
| Creation Time | A fact table is created after dimension tables are created. | The dimension table needs to be created first. |
| Schema Structure | There is less number of fact tables in a schema. | There is a number of dimension tables in a schema. |
What is factless fact in Microstrategy?
A factless fact table is table that doesn’t have fact at all. They may consist of nothing but keys. There are tow types of factless fact table. 1-> event 2-> coverage.
