Can you explain the differences between tabular and multidimensional models, and which among the two is the supported model for Azure analysis services?

Question Analysis

The question asks about the differences between tabular and multidimensional models, and also inquires about which model is supported by Azure Analysis Services. This is a technical question that tests the candidate's understanding of data modeling concepts and their specific knowledge of Azure Analysis Services.

Answer

Tabular vs. Multidimensional Models

• Data Structure:

  • Tabular Model: Uses tables, columns, and relationships, similar to a relational database. It is based on in-memory storage and is optimized for speed and ease of use.
  • Multidimensional Model: Based on OLAP (Online Analytical Processing) cubes, which consist of dimensions and measures, allowing complex calculations and aggregations.

• Development Environment:

  • Tabular Model: Developed using tools like SQL Server Data Tools (SSDT) and supports languages such as DAX (Data Analysis Expressions) for calculations.
  • Multidimensional Model: Developed using Business Intelligence Development Studio (BIDS) or SQL Server Data Tools and supports MDX (Multidimensional Expressions) for querying.

• Performance:

  • Tabular Model: Generally faster for smaller datasets and supports in-memory analytics.
  • Multidimensional Model: Can handle large volumes of data and complex queries but may require more tuning and optimization.

• Ease of Use:

  • Tabular Model: Easier to develop and maintain, with a flatter learning curve, making it more suitable for users familiar with relational databases.
  • Multidimensional Model: More complex, with a steeper learning curve due to the necessity of understanding OLAP concepts.

Azure Analysis Services Support:

Azure Analysis Services primarily supports the Tabular Model. It leverages the in-memory analytics engine to provide high performance and scalability. The tabular model's simplicity and speed make it the preferred choice for many cloud-based analytics solutions.