# 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:

• SQL Server

• Azure Data Warehouse

• Google BigQuery

• IBM Netezza

• Amazon Redshift

• Snowflake

## 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: `<DS_ID>.CORP_DW.DATA.ACCOUNT`. In the Alation UI it would show up as