![]() Here we have discussed Types, How does Dimension Table work in the data warehouse with Advantages.A dimension is a structure that categorizes facts and measures in order to enable users to answer business questions. There are different types of which are used in different scenarios. It contains the dimensions, keys and values of the attributes of the fact table. This is an integral part of data modelling. It gives the context surrounding of any business process.Helps to maintain historical information for any dimension. ![]() The main aim of dimension is to provide the filtering, perform grouping and efficient labelling.īelow are the different advantages of the dimension table: It must be denormalized because their task is to let the user read and analyze the data easily as efficiently rather than managing transactions. It must be ensured that surrogate key (System generated key used during the creation of dimension table which helps to uniquely identify each record present in the dimension table.) must be used while the dimension table is created. While creating it must be kept in mind to filter domain values and store labels of the reports in these tables. Then the dimensional models are generated or build around the business processes. When performing dimension modelling the atomic data is loaded into dimensional structures.When a report is to be created, the user can take the data from as dimension tables contain all the necessary information. When a change is made in any of it then its effect is reflected in that particular table only. Created can be used across different projects and it reflects the idea of reusability. When a dimension is created, a structure of a project is generated. They form a core for dimensional modelling. Dimension refers to the collection or group of information related to any measurable event.It can fulfil multiple purposes within the same existing database. In other words, it is when the same dimension key with all its related attributes is joined to many foreign key presents in the fact table. The having multiple relationships with the fact table are called role-play dimension. ticket number, invoice number, transaction number etc. It attributes which are stored in the fact table itself and not as a separate dimension table, those attributes are called degenerate dimension. But it takes large space hence increases the cost. In this method, the history is saved and can be used whenever necessary. This method is easy to apply and helps to save space hence reduce cost. Let us see an example of a man who travels to different countries so he needs to change his address according to that country. address and phone number changes but not regularly. The dimension attributes that tend to change slowly with time rather than changing in a regular interval of time are called slowly changing dimensions. More columns can be added to the table without affecting the existing applications that are using those.įollowing are the different types of Dimension Table: 1.Its is easy to understand than the normalized tables.Its help to store the history of the information or dimensional information.Hadoop, Data Science, Statistics & others Why do we need to use?
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