> ## Documentation Index
> Fetch the complete documentation index at: https://docs.maia.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# DDL components

DDL (data definition language) components manage the structure of objects in your data warehouse, such as tables, external tables, file formats, streams, and materialized views. Unlike components that load or transform data, DDL components change the shape or configuration of the warehouse itself.

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## Use cases

DDL components are typically used early in a pipeline, to prepare the warehouse objects that later components load data into, or as scheduled maintenance steps that keep those objects performant over time. Use DDL components to:

* Create or replace tables, external tables, and other warehouse objects ahead of a data load.
* Modify the structure of existing objects when your source data or requirements change.
* Remove objects or clear out data that's no longer needed, without affecting the underlying object definition.
* Copy a schema and its objects to a new location, for example when promoting changes between environments.
* Keep external tables, materialized views, and streams up to date with changes in the underlying data.
* Maintain warehouse performance by analyzing, optimizing, or reclaiming storage on existing tables.
* Resize or reconfigure warehouse compute to match the demands of a workload.