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Data warehouse schema generator.

Describe the events you need to measure and the business dimensions used to filter them. The data warehouse schema generator maps fact tables to date, customer, product, store, provider, or other dimensions for a clear analytical model.

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Data warehouse schema examples.

Same tool, four requests. Every drawing below is a real render.

What you type
Create a retail sales gold-layer star schema with dim_date, dim_product, dim_store, dim_customer, and fact_sales tables, the shown keys, attributes, and sales measures, with each fact linked to its date, product, store, and customer dimensions.
Then tryAdd a promotion dimension.Add return transactions.
Entity-Relationship Diagram (ERD): Retail sales gold layer
Entity-Relationship Diagram (ERD) · Chen 1976 / Everest 1976 (crow's foot) · schematex-erd

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The drawing

What a data warehouse schema is.

A data warehouse schema organizes data for analysis rather than transaction processing. Its fact tables hold measurable events, such as sales or claims, while dimension tables hold the descriptive context used to group and filter those events.

A star schema keeps the fact table at the center with dimensions around it, making reporting relationships easy to see. The grain of the fact table—one sale, one claim, or one transaction—should be decided before choosing measures and dimensions.

Standard
Chen 1976 / Everest 1976 (crow's foot)
Also follows
Implements the crow's-foot subset
Engine
schematex-erd
Editable
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Entity-Relationship Diagram (ERD): What a data warehouse schema is
Who uses it

Who uses data warehouse schemas.

Entity-Relationship Diagram (ERD): E-commerce analystsE-commerce analysts

Visits, users, products, referrers, and pages structured for clickstream reporting.

Entity-Relationship Diagram (ERD): Healthcare analytics teamsHealthcare analytics teams

Claims joined to patient, provider, date, diagnosis, and procedure dimensions.

Entity-Relationship Diagram (ERD): Financial analystsFinancial analysts

Transactions measured by date, customer, account, and product for reporting.

How it works

How to make a data warehouse schema in three steps.

01

Describe it

One paragraph is enough to start.

“Create a retail sales gold-layer star schema with dim_date, dim_product, dim_store, dim_customer, and fact_sales tables, the shown keys, attributes, and sales measures, with each fact linked to its date, product, store, and customer dimensions.”
02

See the drawing

Drawn by the right engine.

Entity-Relationship Diagram (ERD): Retail sales gold layer
03

Say what changes

Every edit keeps a version.

Add a promotion dimension.
V2 · DRAWN FROM V1, NOTHING RETYPED
FAQ

Common questions

What is a data warehouse schema?

A data warehouse schema is the structure used to organize data for analysis and reporting. It commonly separates event measures into fact tables and descriptive business context into dimension tables.

What is the difference between a fact table and a dimension table?

A fact table records measurable business events, such as an order amount or claim amount, plus keys to related dimensions. A dimension table describes the event with attributes such as date, product, customer, or location.

What is a star schema?

A star schema places one fact table in the center and connects it directly to dimension tables. It is a common warehouse design because the reporting paths are straightforward.

What is the grain of a fact table?

The grain defines exactly what one row represents, such as one order line, one daily account balance, or one insurance claim. Defining it first prevents mixing measures recorded at different levels of detail.

When should I use a snowflake schema?

Use a snowflake schema when dimensions need to be normalized into related tables, for example when a product dimension links to separate category tables. A star schema is often simpler to query and explain.

Related tools

Other drawings for the same work.

Design a data warehouse schema.

Free account, no card. Describe the event, measures, and dimensions to model.

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