Instructions for developing a model in Rill

Introduction

Models are resources that specify ETL or transformation logic, outputting a tabular dataset to one of the project's connectors. They are typically found near the root of the project's DAG, referencing only connectors and other models.

By default, models output data as a table with the same name as the model in the project's default OLAP connector. The core of a model is usually a SELECT SQL statement, which Rill executes as CREATE TABLE <name> AS <SELECT statement>. The SQL should be a plain SELECT query without a trailing semicolon.

Models in Rill are similar to models in dbt, but support additional advanced features:

• Different input and output connectors: Run a query in one database (e.g., BigQuery) and output results to another (e.g., DuckDB or ClickHouse).
• Stateful incremental ingestion: Track state and load only new or changed data.
• Partition support: Define explicit partitions (e.g., Hive-partitioned files in S3) for scalable, idempotent incremental runs.
• Scheduled refresh: Use cron expressions to automatically refresh data on a schedule.

Model categories