[Feature]: Add Support for Flink Lookup Features

[yuanoOo]

Describe your use case

We would like to enhance the Flink-Connector-OceanBase by adding support for Flink lookup features. This involves two main functionalities:

• Support for Async-Lookup:

  • Implement the async-lookup feature to improve the querying performance by enabling asynchronous operations during the lookup.
  • This would help in reducing the waiting time for I/O operations, thereby increasing the throughput of the system.

• Support for SQL Hint /+ PARALLEL(n) /:

  • Allow passing the /*+ PARALLEL(n) */ hint within SQL queries.
  • This hint should enable parallel execution of queries on OceanBase, allowing better performance for the lookup operations by utilizing parallel processing capabilities.

These enhancements are aimed at making the connector more efficient and scalable when handling lookup queries in Flink.

Describe the solution you'd like

• Deliverables

  • Code implementation for async-lookup support.
  • Unit tests and integration tests to validate the new features.
  • Documentation updates to explain how to use these new functionalities.

Describe alternatives you've considered

No response

Additional context

No response