Slowly Changing Dimensions

Ralph introduced the concept of "slowly changing dimension (SCD)" attributes in 1996.

Slowly Changing Dimensions (SCD) - dimensions that evolve slowly over time, rather than changing the time base in the regular calendar. In the data warehouse, it is necessary to follow the changes of the attributes in the dimension in order to make the data historized. In other words, the implementation of an SCD type must allow users to assign the dimension attribute value appropriate for a given date. Example of these dimensions could be: customer, geography, employee.

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Conditioning the visibility of SSRS columns

In this article, I'm going to show you a real-life example of using the visibility property (Visibility) of the column in SSRS.

Visibility property of the column is used to show or hide the column in the report. Now, in this article, we can use this property to allow users to select the columns they want to display in a report instead of all the columns.

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ADOMD.NET?

In this article we will see how to use ADOMD to interact with an Analysis Services cube.

ADOMD.NET is an extension of ADO.NET. It is a data provider Microsoft .NET Framework that is designed to communicate with Microsoft SQL Server Analysis Services.

Using this extension, we can read the multidimensional schema, query cubes, and retrieve results.

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STG & ODS

We always talk about STG and ODS in BI archi, so what is the role of these two phases in a BI archi?

- STG (Staging Area): is a set of tables that represent a true copy of the data source and are purged each time the ETL is run: it is a waiting area, a "boarding room" before the ODS phase; it is in these tables that we can find data in odd formats.

- ODS (Operating Data Store): is the place where the transformations, the crossings, ... etc; before feeding the datawarehouse and using as source the STG.

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