TMDL view

In the Ultra Transcenders books

DP-600PL-300

Each book explains TMDL view in context, with comparison tables and the common traps.

Terms in this definition

• APPLY

  Evaluates a table-valued expression for every row on its left, inside FROM. Think of OUTER APPLY as a left outer join and CROSS APPLY as an inner join.

• 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.

• Metadata

  Describes data rather than being the data itself, for instance how a file is laid out or what rows each chunk contains, so tools can read things efficiently.

• TMDL

  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.

• Power BI Desktop

  A free Windows program where authors connect to sources, shape and model data, and design reports before publishing them to the Power BI service. Dashboards are not made here.

• LIKE

  Compares strings with a pattern that can contain the % and _ wildcards. Because it only understands character patterns, searching big volumes of text this way is much slower than using full-text search.

• Object-level security

  A semantic model feature that conceals entire tables or columns from a role's members, so they can't even see what exists; it is configured through TMDL view or Tabular Editor. For a SQL database the same term means object permissions set with GRANT and DENY.

Related terms

• Perspective

  Built in TMDL view, this gives readers a narrower, named view of a semantic model, exposing only chosen tables, columns and measures. It can restrict which fields appear when people personalise visuals, yet it provides no security.