feat: Permit SQL based caches to drop dependent objects when swapping temp tables with final ones

[nicob3y]

In the case we use the cache as a built-in destination we might expect that table-dependent objects would be droppped during a refresh. Use case is also described on the Postgres destination connector (https://docs.airbyte.com/integrations/destinations/postgres#creating-dependent-objects)

Summary by CodeRabbit

• New Features
  • Introduced a configurable option allowing users to enable cascade behavior during table removal.
  • Added a process to safely merge temporary tables into final ones, featuring automatic table renaming and error handling for missing table information.

[coderabbitai[bot]]

📝 Walkthrough

Walkthrough

The changes introduce a new boolean attribute drop_cascade to the PostgresConfig class, defaulting to False, which specifies if the CASCADE option should be used when dropping tables. Additionally, a new method _swap_temp_table_with_final_table is added to the PostgresSqlProcessor class. This method swaps a temporary table with a final table by renaming the final table to a temporary deletion alias, renaming the temporary table to the final table, and then dropping the deletion table with an optional CASCADE clause. The method also performs input validation, raising exceptions when necessary.

Changes

File	Change Summary
airbyte/_processors/.../postgres.py	- Added new attribute drop_cascade: bool = False to the PostgresConfig class. - Added _swap_temp_table_with_final_table method to the PostgresSqlProcessor class that swaps tables and conditionally applies the CASCADE clause during table deletion.

Sequence Diagram(s)

sequenceDiagram
    participant Client
    participant Processor as PostgresSqlProcessor
    participant DB as Database

    Client->>Processor: _swap_temp_table_with_final_table(stream_name, temp_table_name, final_table_name)
    alt Missing table names
        Processor-->>Client: Raise Exception
    else Valid table names
        Processor->>DB: Rename final table -> deletion alias
        Processor->>DB: Rename temporary table -> final table name
        Processor->>DB: Drop deletion table (using CASCADE if drop_cascade=True)
        Processor-->>Client: Operation completed successfully
    end

Suggested reviewers

• Should we include bleonard as a reviewer? wdyt?

✨ Finishing Touches

• [ ] 📝 Generate Docstrings

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[aaronsteers]

@nicob3y - Thank you for this contribution! The change looks good to me except I don't think every SQL dialect supports CASCADE.

Could we implement this specifically on Postgres and any other specific cache implementations(s) where needed?

[nicob3y]

@aaronsteers Among the existing cache adapters, only Postgres supports this feature. Therefore, I have created a new option named "drop_cascade" specifically for this adapter; by default, this option is disabled.

How to use it:

from airbyte.caches import PostgresCache

cache_config = {}
cache = PostgresCache(
  **cache_config,
  drop_cascade=True
)