Write Script DuckDB

Use this skill to draft or review DuckDB SQL scripts for local analytics, transformation, and reproducible data work.

Clarify First

• Is the script exploratory, repeatable, or meant for a production-style batch workflow?
• What data sources are involved and what assumptions exist about shape or size?
• Is readability, speed, or reproducibility the main priority?
• Should the output be a table, a report-ready dataset, or a one-off analysis?

DuckDB Guidance

• Keep data-loading assumptions explicit.
• Favor scripts that are easy to rerun and easy to inspect.
• Separate staging, transformation, and final output steps when that improves clarity.
• Think about memory and data-volume expectations even in local workflows.

Good Output

• Query structure with clear stages.
• Notes on assumptions about inputs and outputs.
• Suggestions for making the script easier to rerun or validate.
• Risks around hidden state, temporary objects, or unclear transformations.

Common Mistakes

• Writing a dense one-shot query that is hard to debug.
• Hiding assumptions about input files or schemas.
• Mixing exploration and reusable transformation logic without distinction.
• Treating local analysis code as self-explanatory when it is not.