A YAML-like text format that stores a tabular semantic model as a folder of .tmdl files, for example one per table or role. It maps fully to TOM, works well with source control, and is what a Power BI Project uses by default.
Also called Tabular Model Definition Language.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains TMDL in context, with comparison tables and the common traps.
Terms in this definition
- FORMAT
A DAX function that turns a value into text according to a format string, for instance "MMMM" to show a month's name. Since the output is text, numeric operations can't use it, and dynamic format strings were introduced to get around that.
- Semantic model
Sometimes called an OLAP model, this Power BI and Fabric layer defines the measures, hierarchies, tables and relationships that reports and dashboards query; star schema design is the usual pattern.
- Event
Table in Log Analytics where entries from Windows event logs are kept.
- Role
How an actor normally or expectedly behaves, or the part a person takes in a process. A single actor may hold more than one role.
- MAPS
Short for Microsoft Active Protection Service. It gives Microsoft Defender Antivirus cloud verdicts on suspect files in seconds, and features like file indicators stop working if it is turned off or blocked.
- TOM
A .NET library that extends AMO and lets code create and manage tabular models, including their tables, columns, measures and roles, through the XMLA endpoint.
- CONTROL
Granting this on a securable gives all other permissions on it too, making it the most powerful SQL permission. At database scope that includes UNMASK and ALTER ANY MASK. Warehouse access through the Admin, Member or Contributor workspace roles carries it.
- PBIP
A project format for Power BI Desktop in which the report and model are saved as plain-text definitions in folders, not as a single binary file, making Git and CI/CD practical. Switching to or from .pbix happens only via Save as.
Related terms
- TMDL view
Lets you script, edit and apply semantic model metadata as TMDL code, in Power BI Desktop or (preview) the service. Some objects, like perspectives or object-level security, can only be edited this way.