Introduction to the TCDX Model

Overview

The TCDX Model is a structured framework designed to standardize tabular model metadata tracking, focusing on two primary entities: Consumers and QueryGroups. These elements capture essential metadata on how Power BI and SQL Server Analysis Services (SSAS) tabular models are utilized, facilitating performance analysis, governance, and interoperability across multiple tools.

The TCDX format is a community-driven project aimed at becoming a universal standard for metadata extraction and model tracking. It is intended for adoption, extension, and modification by various BI tool vendors and developers. Implementers must map their tools’ requirements to the TCDX object model and may contribute improvements to enhance the framework.

By offering a common metadata structure, TCDX brings consistency, cross-platform compatibility, and efficient data governance to the BI ecosystem.

TCDX and the BI Tools Developer Community

The TCDX format is designed to be an open standard, enabling BI professionals, vendors, and tool developers to:

• Adopt a unified metadata structure across Power BI, Excel, and SSAS tools.
• Extend and modify the model to accommodate specific tool requirements.
• Contribute to the community, ensuring continuous improvement and scalability.

Since TCDX is a work in progress, its growth depends on community engagement and collaboration. The Power BI and SSAS communities can drive innovation and adoption by:

• Standardizing metadata structures for improved cross-tool compatibility.
• Optimizing model performance through query execution insights.
• Enhancing governance and data lineage tracking, ensuring transparent model usage.

As more BI tools integrate TCDX, it will serve as a common framework for tracking and optimizing tabular model usage across different reporting environments.

TCDX Object Model

The TCDX Object Model is structured around three key components:

1. Consumers

A Consumer represents a client application that interacts with a tabular model, such as:

• Excel workbooks (pivot tables, Power Query connections).
• Power BI reports (DAX queries, visuals).
• Other BI tools leveraging tabular models.

Each Consumer contains:

• Metadata about its type (Excel, Power BI Service, Power BI Desktop).
• Host system details (file path, cloud environment).
• A collection of Items, representing pivot tables, reports, and visuals.
• Dependencies on tables, columns, and measures.

Consumers are grouped under a ConsumersCollection, allowing for efficient management of multiple Consumers in a single TCDX file.

2. QueryGroups

A QueryGroup captures queries executed against a tabular model, tracking:

• Query execution sources (Query Analytics, SQL Profiler, Extended Events).
• Performance statistics, including query frequency and execution times.
• References to data elements (tables, columns, measures).

QueryGroups help organizations optimize queries, refine data models, and improve reporting efficiency. They are stored in a QueryGroupsCollection, organizing query execution data effectively.

3. Model Dependencies

Model dependencies define relationships between Consumers, QueryGroups, and tabular models, including:

• ModelDependency: The referenced tabular model.
• TableDependency: The referenced tables in the model.
• ColumnDependency: The referenced columns in the tables.
• MeasureDependency: The referenced measures used in calculations.

These relationships enhance visibility into data interactions, helping BI professionals optimize reporting and data governance.

TCDX as an Industry Standard

The TCDX format aims to be the de facto standard for tabular model metadata tracking, with an open architecture that enables:

• Adoption by multiple BI tools and vendors, ensuring interoperability.
• Community-driven development, allowing implementers to contribute and refine the model.
• Scalability and extensibility, ensuring that TCDX can evolve with BI industry needs.

TCDX relies on collaboration from the Power BI and SSAS communities to:

• Standardize metadata structures for seamless cross-platform use.
• Enhance model performance through detailed query analytics.
• Strengthen governance and data lineage tracking for better reporting transparency.

As more BI tools integrate TCDX, it will become the standard framework for managing tabular model interactions, improving efficiency, performance, and governance.

TCDX File Format

TCDX metadata is stored in a ZIP-compressed archive, containing JSON-serialized metadata representing:

• Consumers (reporting tools interacting with the model).
• QueryGroups (executed queries and performance metrics).

This format is:

• Optimized for integration with BI tools, automation scripts, and DevOps pipelines.
• Structured for scalability, supporting multi-tool, multi-environment use cases.
• Designed for extensibility, allowing future metadata enhancements.

Integration and Tools

TCDX is supported by open-source .NET libraries and a command-line tool (CLI) that simplify:

• Data extraction from Power BI, Excel, and SSAS models.
• Query performance analysis to enhance reporting efficiency.
• DevOps integration for automated monitoring and optimization.

TCDX Libraries

The TCDX libraries are hosted on GitHub and available on NuGet:

• Dax.Tcdx.Metadata
  Provides a structured representation of Consumers and QueryGroups.

• Dax.Tcdx
  Enables reading and writing TCDX files.

• Dax.Tcdx.Module.Unifier
  Supports merging multiple TCDX files.

TCDX Command-Line Tool

The TCDX CLI is a .NET-based tool whose purpose is to automate:

• Query execution tracking.
• Metadata extraction and storage.
• Report dependency analysis.

Note:

tcdx cli is a work in progress, it now contains the unifier tool, used to merge tcdx files.

Installation

To install:

dotnet tool install Dax.Tcdx.CLI --global
tcdx --help

Tcdx Libraries

The Tcdx libraries source code is available in the Tcdx GitHub repository. Each module has a corresponding NuGet package:

• Dax.Tcdx.Metadata is a representation of the Consumers and QueryGroups using a tabular models. This is a .NET Standard library without dependencies on the Tabular Object Model (TOM). It has a dependency on Dax.Metadata that is the core of VertiPaq Analyzer and includes all the information about the data model the consumers and the queries are referring to.
• Dax.Tcdx Library to read and write Tcdx files. This library is a .NET Standard library.
• Dax.Tcdx.Module.Unifier Library to unify Tcdx files. This library is a .NET Standard library.

Tcdx Format

The TCDX file format is a ZIP file containing the json serialization of the object models for Consumers and Queries:

Tools

• Pivot Scanner: repository yet to be created for the PivotScanner and ExportPivotScan tools