Catalogs¶
Catalogs are used to store all metadata about database objects, such as tables, table attributes, functions, and views. The catalog metadata is accessed when a SQL query is parsed, validated, and optimized. Only database objects which are registered in a catalog can be referenced in SQL queries.
Ververica Platform’s Built-In Catalog¶
Every namespace has a separate, built-in catalog named vvp that contains a single database named default.
Note
Since default is a keyword in SQL, you need to escape the name of vvp’s default database as `default`.
The fully-qualified name of a table myTable that is registered in the built-in catalog is vvp.`default`.myTable.
However, you do not need to reference tables and functions with their fully-qualified names because the catalog only supports a single database at this point.
Features of the Built-In Catalog¶
The following database objects are currently supported by VVP’s built-in catalog:
- Tables
- See Databases, Tables & Views to learn how to create, alter, and drop tables.
- User-Defined Functions
- See Functions to learn how to implement and manage user-defined functions.
Not supported features at this point are:
- Views
- Additional Databases
- Table Partitions
- Table, Column, and Partition Statistics
We will add these features in future releases depending on user feedback.
Support for External Catalogs¶
External catalogs manage metadata for tables and expose this information to other systems. Ververica Platform does not yet support external catalogs. We are planning to add support for the following external catalogs in upcoming releases:
- Apache Hive™ Metastore
- Confluent Schema Registry for Apache Kafka®