Domains

You can use domains anywhere corresponding base type can be used, for example:

• Create a column of a domain type
• Use it as an index if a base type can be used as an index
• Call functions with values of domain column

• Explicit column type name in or DESCRIBE TABLE
• Output to human-friendly format for SELECT domain_column FROM domain_table
• Loading data from an external source in the human-friendly format:

Limitations

• Can’t convert index column of base type to domain type via ALTER TABLE.
• Domain adds no constrains on stored values.