# Multipart Schema Names
The Alation Catalog models data sources as a three-level hierarchy: Schema > Table > Column. Different data source types refer to the top level in different ways (schema, catalog, or database), but in Alation any object that contains a group of tables or views is a "schema."
Some data source types have an extra level in the hierarchy. Above a group of tables is another grouping - a group of groups of tables, or a group of schemas. In Alation, this upper level is collapsed into the schema level. In this case, a "schema" in Alation has a multipart name in the format "parent.child".
The following data source types have multipart schema names:
Azure Data Warehouse
## Snowflake Example:
In the below image, we can see how `
CORP_DW` is the database, `
DATA` is the schema, and `
ACCOUNT` is the table.
In Alation, the `
key` for the ACCOUNT table would be: `
In the Alation UI it would show up as