Principle:Apache Paimon Catalog Initialization
| Knowledge Sources | |
|---|---|
| Domains | Data_Lake, Table_Format |
| Last Updated | 2026-02-07 00:00 GMT |
Overview
Mechanism for creating and configuring data lake catalog connections based on storage backend type.
Description
Catalog initialization is the entry point for interacting with a data lake table format. It resolves the appropriate catalog implementation (filesystem or REST) based on configuration options. The Factory Pattern is used to abstract the catalog creation from the consumer, allowing different backends (local filesystem, cloud object stores, REST servers) to be configured uniformly via a dictionary of options. By centralizing catalog creation behind a single factory method, the system decouples client code from specific catalog implementations, enabling seamless switching between storage backends without modifying application logic.
Usage
Use this principle when establishing a connection to a Paimon table catalog. This is required as the first step in any Paimon workflow. All subsequent operations -- database creation, table creation, reading, and writing -- depend on a properly initialized catalog instance. The caller provides a dictionary of configuration options specifying the metastore type, warehouse path, and any authentication tokens, and receives a fully configured catalog object ready for use.
Theoretical Basis
Follows the Factory Method design pattern. A single static factory method dispatches to the correct catalog class based on the metastore configuration key. The factory maintains a registry mapping metastore type strings (e.g., 'filesystem', 'rest') to their corresponding catalog classes. This approach provides several benefits:
- Abstraction: Consumers interact with a uniform
Cataloginterface regardless of the underlying storage backend. - Extensibility: New catalog types can be added to the registry without modifying existing client code.
- Configuration-driven: The catalog type is determined entirely by runtime configuration, enabling environment-specific deployments (local development vs. cloud production) without code changes.