dax
The dax skill provides a structured framework for optimizing DAX query performance in Power BI semantic models. It organizes optimization into four tiers with corresponding reference materials on engine internals, DAX patterns, model design, and Direct Lake approaches, alongside guidance on trace capture and profiling using either Power BI Desktop or Fabric Service tools. Use it when asked to optimize slow DAX queries, debug measures, identify anti-patterns, or improve semantic model performance.
git clone --depth 1 https://github.com/data-goblin/power-bi-agentic-development /tmp/dax && cp -r /tmp/dax/plugins/semantic-models/skills/dax ~/.claude/skills/daxSKILL.md
# DAX Skills and references for writing, debugging, and optimizing DAX in semantic models. ## Optimization For systematic DAX query performance optimization, read the workflow reference first: **[`references/dax-performance-optimization.md`](./references/dax-performance-optimization.md)** — Tiered framework (4 tiers), phased workflow, decision guide, and error handling. Detailed reference files (progressive disclosure — consult as directed by the workflow): - **[`references/engine-internals.md`](./references/engine-internals.md)** — FE/SE architecture, xmSQL, compression/segments, SE fusion, trace diagnostics - **[`references/dax-patterns.md`](./references/dax-patterns.md)** — Tier 1 DAX patterns (DAX001–DAX021) + Tier 2 query structure (QRY001–QRY004) - **[`references/model-optimization.md`](./references/model-optimization.md)** — Tier 3 model patterns (MDL001–MDL009) + Tier 4 Direct Lake (DL001–DL002) Trace capture and performance profiling: - **Local models (Power BI Desktop):** Use the [`connect-pbid` skill](../../../pbi-desktop/skills/connect-pbid/) — specifically `performance-profiling.md` for FE/SE timing and `evaluateandlog-debugging.md` for intermediate result inspection. - **Remote models (Fabric Service / XMLA):** Use the [`powerbi-modeling-mcp`](https://marketplace.visualstudio.com/items?itemName=analysis-services.powerbi-modeling-mcp) VS Code extension for trace and query operations. Install: `code --install-extension analysis-services.powerbi-modeling-mcp` ## Related Skills - [`semantic-model`](../semantic-model/) — Model design, build, and auditing including DAX anti-patterns and best practices - [`connect-pbid` (pbi-desktop plugin)](../../../pbi-desktop/skills/connect-pbid/) — Trace capture, performance profiling, EVALUATEANDLOG debugging - [`lineage-analysis`](../lineage-analysis/) — Impact analysis before model changes
Automatically invoke this skill whenever the user asks about Fabric tenant settings or Power BI tenant settings or auditing tenant settings. You can use this skill if the user mentions "Fabric administration".
Expert guidance for using the Fabric CLI (`fab`) to fully interact with Fabric workspaces, items, and configuration. Automatically invoke this skill whenever the user mentions "Fabric" or "Power BI Service" or a "Fabric/Power BI workspace".
TOM and ADOMD.NET guidance via PowerShell for connecting to Power BI Desktop's local Analysis Services instance. Covers model enumeration, DAX queries, metadata modification, annotations, calendar definitions, field parameters, query tracing, DAX library package management (daxlib.org), and the Desktop Bridge for reloading and screenshotting the report canvas. Automatically invoke when the user mentions "Power BI Desktop", "Analysis Services port", "TOM", "ADOMD", "daxlib", "DAX library", "DAX UDF package", or asks to "connect to PBI Desktop", "query PBI Desktop with DAX", "modify PBI Desktop model", "add a measure to PBI", "capture visual queries", "create a field parameter", "validate DAX", "intercept DAX queries", "install daxlib", "add DAX SVG", "add IBCS", "reload the report canvas", "screenshot a report page", "Desktop Bridge", or to work with the model and report in Power BI Desktop together.
Expert guidance for the Power BI Project (PBIP) file format; project structure, cross-cutting operations (renames, forking), and PBIX extraction/conversion. Automatically invoke when the user mentions PBIP, PBIX, .pbip/.pbism/.platform files, or asks about "PBIP project structure", "PBIP vs PBIX", "thin report vs thick report", "rename a table", "cascade rename", "fork a PBIP project", "convert pbix to pbip", "extract pbix", "what files are in a PBIP", "PBIP encoding", "definition.pbir", or discusses project-level file structure and post-rename verification.
Format reference for Power BI Enhanced Report (PBIR) JSON schemas and patterns. Automatically invoke when the user asks about PBIR JSON structure, visual.json properties, PBIR expressions, objects vs visualContainerObjects, theme inheritance, conditional formatting patterns, extension measures, bookmarks, field references, filter formatting, query roles, PBIR page structure, report wallpaper, or any PBIR metadata format question.
Direct TMDL file authoring and BIM-to-TMDL conversion for semantic models in PBIP projects. Automatically invoke when the user asks to "edit TMDL", "add a measure in TMDL", "TMDL syntax", "fix formatString", "fix summarizeBy", "TMDL indentation", "convert BIM to TMDL", "add a column description", "create a calculated column in TMDL", or mentions .tmdl file editing or BIM-to-TMDL migration.
Step-by-step workflow for creating complete Power BI reports from scratch using pbir CLI. Covers model discovery, report creation, page layout, theme setup, visual placement, field binding, filtering, formatting, validation, and publishing. Automatically invoke when the user asks to "create a new report", "build a report from scratch", "make a dashboard", "set up a report with KPIs", "create an executive dashboard", "add pages and visuals to a new report".
Deneb visual creation, Vega/Vega-Lite spec authoring, and Deneb best practices for PBIR reports. Automatically invoke whenever the user mentions "Deneb" in any context, or asks about Vega/Vega-Lite specs in Power BI, Deneb cross-filtering, Deneb interactivity, pbiColor theme integration, Deneb field name escaping, or Deneb rendering issues.