01-grain-definition

What problem does it solve?

This Skill prevents costly data warehouse table rewrites by ensuring fact table grain is unambiguously defined during the Gold layer design phase, catching ambiguities before implementation.

Core Features & Use Cases

• Grain Definition: Provides patterns and decision trees for identifying transaction, aggregated, and snapshot fact table grains.
• YAML Documentation: Guides users on how to explicitly document grain type and primary keys in YAML schemas.
• Use Case: When designing a new fact table for sales transactions, this skill helps determine if it should be transaction-level (one row per sale) or aggregated (e.g., daily sales per product), ensuring the correct primary key and merge logic are applied from the start.

Quick Start

Use the 01-grain-definition skill to document the grain for a new fact table by providing its primary key columns and intended measures.