Schema metadata¶
A schema metadata document optionally describes an item-owned schema or declares a schema that no other document uses. Object, validation and non-schema Shortcut identities imply their schemas, so a separate file is not required merely to create a normal object namespace.
Location and identity¶
Schema metadata is supported in both item types at:
The file sits directly under schemas/. <Schema>.yml and Schema ID must match exactly, including case. Schema ID is one non-empty bare name: whitespace, forward slash, backslash, dot and colon are not accepted. Exact duplicates and case-only collisions with explicit or implied schemas are errors.
Keys¶
| Key | Required | Value and default |
|---|---|---|
Schema ID |
Yes | One bare schema name matching the filename. |
Description |
No | Non-empty string when present. Default: no description. |
No other keys are accepted. This file has no SQL or Python body, dependency declaration, class, method or return form. Its Description is literal schema prose; the object-metadata $... reference syntax is not interpreted here.
Path: Lakehouse/Curated/schemas/Parcel.yml or Warehouse/Reporting/schemas/Parcel.yml.
Operations and managed state¶
- Check validates the YAML mapping, allowed keys, identity agreement and collisions.
- Build includes an explicit schema document in the owning item's source signature. Physical schema creation is planned when a selected object, programmable or non-schema Shortcut needs that schema; a standalone unused schema document is valid source but does not by itself select a physical schema for creation. A file describing a schema already implied by another declaration changes that one schema's metadata rather than creating a second identity.
- Load and Test do not execute schema metadata.
For schemas used by retained installed declarations, _.SchemaDictionary records item type, item name, schema name, optional description, a null description reference and the schema signature. Inferred schemas have no authored description and use a deterministic signature derived from the schema name. Ordinary schema declarations do not add a load or test status and have no managed row-audit or business columns of their own.