Improving Migration Order Clarity in fastn

[Arpita-Jaiswal]

Currently, fastn migrations require users to manually add migration entries in the correct order, from bottom to top. This method can lead to confusion and errors, as shown in the example below:

-- fastn.migration: alter-foo-add-c

ALTER TABLE foo ADD COLUMN c

-- fastn.migration: initial

CREATE TABLE foo(a, b);

In this scenario, users must ensure the initial migration is listed after the alter-foo-add-c migration to maintain the correct order of operations. This can be counterintuitive and error-prone.

Proposed Solution

To improve the clarity and reliability of migration orders, we propose introducing a number field in each migration entry. This change will ensure that migrations are applied in a strictly increasing sequence, removing the ambiguity for users.

-- fastn.migration: alter-foo-add-c
number: 2

ALTER TABLE foo ADD COLUMN c

-- fastn.migration: initial
number: 1

CREATE TABLE foo(a, b);

Benefits

• Clear Ordering: Users can easily see the order of migrations, reducing confusion and potential errors.
• Validation: fastn will enforce that migration numbers are strictly increasing, preventing out-of-order migrations.