---
name: DAX
slug: dax
category: Data
description: DAX optimizes and debugs DAX measures in semantic models. Use it when a measure is slow, needs tuning, or you need help with DAX performance issues and anti-patterns.
github: "https://github.com/data-goblin/power-bi-agentic-development/tree/main/plugins/semantic-models/skills/dax"
language: "C#"
stars: 872
forks: 129
install: "npx degit https://github.com/data-goblin/power-bi-agentic-development/tree/main/plugins/semantic-models/skills/dax ~/.claude/skills/dax"
installs_to: ~/.claude/skills/dax
source_path: plugins/semantic-models/skills/dax/SKILL.md
collection_size: 25
category_size: 668
collection_url: "https://dirskills.com/collections/data-goblin/power-bi-agentic-development"
added: 2026-08-22T05:21:31.476Z
last_synced: 2026-08-22T05:21:31.476Z
canonical_url: "https://dirskills.com/skills/dax"
---

# DAX

DAX optimizes and debugs DAX measures in semantic models. Use it when a measure is slow, needs tuning, or you need help with DAX performance issues and anti-patterns.

**Install:**

```bash
npx degit https://github.com/data-goblin/power-bi-agentic-development/tree/main/plugins/semantic-models/skills/dax ~/.claude/skills/dax
```

## README

# 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 Tabular Editor CLI `te query` (see the [`te-cli` skill](../../../tabular-editor/skills/te-cli/)) first; as an alternative, the [`connect-pbid` skill](../../../pbi-desktop/skills/connect-pbid/) covers FE/SE timing (`performance-profiling.md`) and intermediate result inspection (`evaluateandlog-debugging.md`).
- **Remote models (Fabric Service / XMLA):** Run DAX with the Tabular Editor CLI `te query` (`-s <workspace> -d <model>`) against the workspace XMLA endpoint; see the [`te-cli` skill](../../../tabular-editor/skills/te-cli/) (tabular-editor plugin).
- **Power BI Modeling MCP:** also available for trace and query if you prefer an MCP tool; reach for it after the options above.

## 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