Introduction to Data Entry Matrix v26.1

Power ON’s Data Entry Matrix (DEMx) is a custom visual designed for Microsoft’s Power BI. It enhances the user experience by enabling end users to make permanent changes to data through write-back functionality. This means users can target measures and DAX expressions to modify data directly within their reports.

The Data Entry Matrix product documentation provides a detailed overview of the matrix and how to use it in reports. It covers common use-case implementations, proper configuration, and strategies for overcoming potential pitfalls. This documentation caters to both technical experts (such as developers, DBAs, and BI professionals) who have in-depth knowledge of SQL Server, SSAS Tabular models, Azure Services, and Power BI, as well as users who primarily concentrate on creating and preparing reports using Power BI Desktop. Some topics delve into more technical subjects.

Data Entry Matrix enables users to modify figures that result from DAX expressions defined aggregations. In traditional dimensional modeling, these aggregations are calculated on fact tables, with the calculation context defined by the dimension or lookup tables that are in relation with the fact table. DEMx enables users to update the results of their measures.

Key features of DEMx include:

• Writing back values to the underlying data source.
• Modifying figures by using smart formulas or exact values.
• Updating values not only at the individual cell level but also at the aggregated levels - totals and subtotals. These changes cascade down to the corresponding members.
• Creating comments on cells.
• Copying and pasting selected cells to and from the visual.
• Copying the entire matrix along with headers.
  • Press CTRL+A on your keyboard to select the entire data table (including corner cells, header cells, and content cells).
  • Press CTRL+C on your keyboard to copy the selected content to the clipboard.
• Dragging pop-up windows using their title to arrange the interface as needed.

Following is the high-level overview of how write-back works for Tabular models. Depending on your data source (SSAS In-Memory, SSAS Direct Query, or SQL only) Power ON’s write-back service performs the following steps:

1. The service captures the modified value along with its tuple (the intersection of dimensions used in the calculation of measure for the given cell) and the user context. Based on the SSAS model structure (relationships, table queries, and measure definitions) the service composes T-SQL statements for execution.
2. It executes the compiled T-SQL statement against the underlying data source (fact table) to save the modifications.
3. For SSAS in-memory models, the service reprocesses the table. See Performance Optimization for more information.
4. It refreshes the visual to display the changes in the report.