TMDL View

[powerbiexpert22]

i have gone through below document and understood that TMDL view is used to srite scripts in TMDL language to customize semantic model however i am not sure in which scenario we should use TMDL 

Use Tabular Model Definition Language (TMDL) view in Power BI Desktop - Power BI | Microsoft Learn

[danextian · Accepted solution]

One of the most useful applications of TMDL is copying a table from one PBIX file to another. While it is possible to copy the query or M code directly, that approach does not carry over calculated columns, column formatting, or other semantic model metadata. TMDL preserves these elements, making it much easier to replicate tables across models.

It can also be used to change the storage mode of a table from import to Direct Query although you have to ensure that none of the applied steps breaks query folding as the switch will not take affect.

TMDL is also useful for creating a backup of a semantic model's state. Before making changes, the entire semantic model can be scripted to TMDL. If measures, columns, or other semantic model objects are accidentally deleted, the previously generated TMDL script can be reapplied to restore them.

However, TMDL only affects the semantic layer. It cannot recover deleted report pages and visuals.

[v-moharafi-msft]

Hi  @powerbiexpert22   ,

Thank you for reaching out to Microsoft Fabric Community and Thanks to @krishnakanth240 , @danextian   and    @MFelix    for Sharing valuable insights.

Just wanted to check if you had the opportunity to review the information provided. Please feel free to contact us if you have any further questions. 

 Best Regards,

Abdul Rafi.

[krishnakanth240 · Accepted solution]

Hi @powerbiexpert22 

TMDL View is useful when you need to manage and modify semantic model metadata at scale. Instead of manually creating or editing measures, relationships and calculation groups you can define them as code using TMDL. 

Common scenarios include version control with Git, deploying model changes across environments, editing measures, collaborating with developers, and tracking model changes in source control.

https://youtu.be/WGMIoteHMs4?si=VTXOG_5mW30Zn5bU

https://youtu.be/lnuaD4gIBe4?si=UYVx71DbgIT35bsi

https://youtube.com/playlist?list=PLL5m0piY28pjojhP-nKKXaXieiHSwchvp&si=2nZszEGGC

[danextian · Accepted solution]

One of the most useful applications of TMDL is copying a table from one PBIX file to another. While it is possible to copy the query or M code directly, that approach does not carry over calculated columns, column formatting, or other semantic model metadata. TMDL preserves these elements, making it much easier to replicate tables across models.

It can also be used to change the storage mode of a table from import to Direct Query although you have to ensure that none of the applied steps breaks query folding as the switch will not take affect.

TMDL is also useful for creating a backup of a semantic model's state. Before making changes, the entire semantic model can be scripted to TMDL. If measures, columns, or other semantic model objects are accidentally deleted, the previously generated TMDL script can be reapplied to restore them.

However, TMDL only affects the semantic layer. It cannot recover deleted report pages and visuals.

[MFelix]

Hi @powerbiexpert22 ,

TMDL view is uses when you want to make changes programatically to your model.it allows you to quickly update any definition on your model from renaming tablets colums or measure to Turn on and off definitions that otherwise would ONLY BE available trough external tools.

When you use the ui/ux experience depending on your model you can have a very slow experience using script the update is instantly. Moreover it allows for searxh and replace that allows to do bulk renames or update of specific propoerties.

This scripts can also be rerun só if you have a calendar table for examples or a calculatoon group, firld parameter that you use and reuse on sevral model you just have to Run the script on the new model and  on instant you get it.

This is also available for the online modelos allowing you to mKs changes to your model easily without the need to repunlish trough Power bi desktop.

On my opinion is a very powerfull tools and depending on the size of your model and what you want to do is very flexible and take your development to the Next level.