Question

What is the role of composite models in Power BI, and how can they enhance performance?

I'm building a Power BI report that integrates data from both direct query and imported sources. I’m exploring the use of composite models to combine these different data sources and optimize performance. However, I’m not fully clear on how to effectively use composite models without compromising report speed or flexibility.

What is the role of composite models in Power BI, and how can I leverage them to improve report performance while working with different data sources?

Answer 1

• “Composite models” in Power BI refer to a simplistic yet highly effective functionality that brings together two modes of working, import, and DirectQuery, in a single report. This mix offers the best of both worlds in terms of ease and performance, considering it allows querying of big data very efficiently without the need to ingest all of that data into Power BI’s RAM. Following the use of a composite model allows one to take the most suitable data access optimization approach depending on how large the data is, how often it changes, and how quickly the information must be available.

• The primary benefit of composite models is the ability of users to maintain high-volume, rapidly changing datasets in DirectQuery, which only on-demand requests data from the source without importation, allowing for heavy memory usage. In contrast, smaller and static tables can be updated in Power BI, which preaches some portion of the data, thus enabling faster report generation. For instance, it is convenient to use DirectQuery for a transactional table while importing a reference table that has no changes such that it is usually better to cache it.

• In order to implement composite models properly and boost the overall performance, see that the DirectQuery tables are well managed at the source to minimize the query and remove any redundant column or row. In addition, Power BI storage modes give you the ability to specify which tables are Direct Query and which ones are imported so that you can arrange the reports in a way that they are fast or real-time as you want. In addition to this, applying aggregate tables and properly establishing a relation between DirectQuery and imported tables enhances the performance even more. Such a combination of factors accounts for why composite models enable the creation of a fast and dynamic report that uses both access methods to its best advantage.

Answer 2

Composite models in Power BI allow for the combination of DirectQuery and Import modes within the same report, providing flexibility to handle large datasets efficiently. To balance performance and scalability, use DirectQuery for live data access and Import for frequently used static data. Ensure proper relationships and aggregations to optimize query performance. Limit the use of complex measures to avoid slow queries.