No support for dynamic defaults

Oct 13, 2025 by talynt.org 126 views

Problem

When working with databases, adding a primary key column can be a straightforward process. However, there are some limitations and rough edges to this approach. Currently, it's possible to add a primary key column by first adding a column and then designating it as the primary key. However, this method has several drawbacks:

Lack of atomicity: If there's already a primary key column in the table, adding a new column and then designating it as the primary key can result in the previous primary key column still being recognized as the primary key. This can lead to confusion and errors in database management.
No support for dynamic defaults: When adding a primary key column, it's not possible to set dynamic defaults, which can be a limitation in certain scenarios.

Proposed Solution

To address these limitations and provide a more streamlined experience for database management, we propose adding a new RPC function called add_pkey_column. This function will enable users to add a primary key column in a single, atomic operation, without the need for workarounds or manual intervention.

The `add_pkey_column` Function

The add_pkey_column function will take the following parameters:

database_id: The ID of the database where the primary key column will be added.
table_oid: The OID of the table where the primary key column will be added.
pkey_type: The type of primary key to be added, which can be either 'IDENTITY' or 'UUIDv4'.
column_name: The name of the primary key column to be added.

Here's an example of what the add_pkey_column function might look like in Python:

def add_pkey_column(
    database_id: int, table_oid: int, pkey_type: Literal['IDENTITY', 'UUIDv4'], column_name: Optional[str]
) -> void

Benefits of the `add_pkey_column` Function

The add_pkey_column function will provide several benefits, including:

Atomicity: The function will add the primary key column in a single, atomic operation, ensuring that the previous primary key column is not affected.
Simplified database management: The function will eliminate the need for workarounds and manual intervention, making database management easier and more efficient.
Improved flexibility: The function will allow users to set dynamic defaults, providing more flexibility in database management.

Implementation Details

To implement the add_pkey_column function, we will need to:

Create a new RPC function: We will create a new RPC function that takes the required parameters and performs the necessary operations to add the primary key column.
Implement atomicity: We will ensure that the function adds the primary key column in a single, atomic operation, without affecting the previous primary key column.
Support dynamic defaults: We will implement support for dynamic defaults, allowing users to set default values for the primary key column.

Conclusion

The add_pkey_column function will provide a more streamlined experience for database management, eliminating the need for workarounds and manual intervention. By adding a primary key column in a single, atomic operation, the function will improve flexibility and simplify database management. We believe that the add_pkey_column function will be a valuable addition to our database management tools.

Future Work

In the future, we plan to:

Refine the implementation: We will refine the implementation of the add_pkey_column function to ensure that it meets the required standards and is efficient in its operations.
Add additional features: We will consider adding additional features to the add_pkey_column function, such as support for multiple primary key columns or the ability to modify existing primary key columns.

References

Appendices

Appendix A: Implementation Details
- This appendix provides additional details on the implementation of the add_pkey_column function, including the code and any relevant technical details.
Appendix B: Testing and Validation
- This appendix provides information on the testing and validation of the add_pkey_column function, including any relevant test cases and validation procedures.
  Frequently Asked Questions (FAQs) about the add_pkey_column Function ====================================================================

Q: What is the purpose of the `add_pkey_column` function?

A: The add_pkey_column function is designed to add a primary key column to a table in a database in a single, atomic operation. This eliminates the need for workarounds and manual intervention, making database management easier and more efficient.

Q: What are the benefits of using the `add_pkey_column` function?

A: The benefits of using the add_pkey_column function include:

Atomicity: The function adds the primary key column in a single, atomic operation, ensuring that the previous primary key column is not affected.
Simplified database management: The function eliminates the need for workarounds and manual intervention, making database management easier and more efficient.
Improved flexibility: The function allows users to set dynamic defaults, providing more flexibility in database management.

Q: What are the parameters of the `add_pkey_column` function?

A: The add_pkey_column function takes the following parameters:

database_id: The ID of the database where the primary key column will be added.
table_oid: The OID of the table where the primary key column will be added.
pkey_type: The type of primary key to be added, which can be either 'IDENTITY' or 'UUIDv4'.
column_name: The name of the primary key column to be added.

Q: What are the supported primary key types?

A: The add_pkey_column function supports two primary key types:

IDENTITY: This type generates a unique identifier for each row in the table.
UUIDv4: This type generates a unique identifier for each row in the table using a UUIDv4 algorithm.

Q: Can I modify an existing primary key column using the `add_pkey_column` function?

A: No, the add_pkey_column function is designed to add a new primary key column, not modify an existing one. If you need to modify an existing primary key column, you will need to use a different function or approach.

Q: What are the potential errors or issues that may occur when using the `add_pkey_column` function?

A: Some potential errors or issues that may occur when using the add_pkey_column function include:

Database connection errors: If the database connection is lost or fails, the function may not complete successfully.
Table or column not found errors: If the table or column does not exist, the function may not complete successfully.
Primary key type not supported errors: If the primary key type is not supported, the function may not complete successfully.

Q: How do I troubleshoot issues with the `add_pkey_column` function?

A: To troubleshoot issues with the add_pkey_column function, you can:

Check the database connection: Ensure that the database connection is stable and functioning correctly.
Verify the table and column existence: Ensure that the table and column exist and are correctly named.
Check the primary key type: Ensure that the primary key type is supported and correctly specified.

Q: Can I use the `add_pkey_column` function in a production environment?

A: Yes, the add_pkey_column function can be used in a production environment. However, it's recommended to thoroughly test the function in a non-production environment before deploying it to production.

Q: What are the future plans for the `add_pkey_column` function?

A: Future plans for the add_pkey_column function include:

Refining the implementation: We will refine the implementation of the add_pkey_column function to ensure that it meets the required standards and is efficient in its operations.
Adding additional features: We will consider adding additional features to the add_pkey_column function, such as support for multiple primary key columns or the ability to modify existing primary key columns.