Repair Django Migration Partial Index Concurrent Build

Failed concurrent index builds in PostgreSQL often leave Django migrations in a broken, inconsistent state. Standard migration commands fail because the index exists but is marked as invalid, while Django believes the migration hasn't run. This skill provides a structured diagnostic and recovery path to clean up these orphaned indexes and safely re-apply migrations.

What it does

• State Reconciliation compares Django's django_migrations table against the Postgres pg_index catalog to find mismatches.
• Invalid Index Detection identifies partial or failed CONCURRENTLY builds that are blocking deployment pipelines.
• Migration Decoupling separates non-atomic steps to prevent repeat failures during the retry phase.
• Reverse/Rerun Design generates specific SQL and Django commands to drop invalid indexes and re-trigger migrations safely.

How it works

1. Provide the skill with the failed migration file, Postgres index catalog logs, and deployment stderr output.
2. The skill executes four mandatory checks to identify the decision boundary and unresolved risks.
3. It generates a migration-to-index map and a disposition report for any invalid indexes found.
4. You receive a step-by-step recovery plan with rollback-safe deployment assertions.

Frameworks & tools

This skill is designed for Django web applications using PostgreSQL databases. It focuses on the interaction between Django's migration engine and Postgres-specific concurrent index operations.

Why this beats prompting it yourself

Manual cleanup of failed concurrent indexes is error-prone and often leads to duplicate index attempts or blocked deployments. This skill enforces an evidence-first workflow that requires verification of the Postgres catalog before suggesting any destructive DROP INDEX commands.

Use cases

• Fix deployments stuck on Index already exists errors during concurrent builds.
• Clean up invalid indexes left behind after a CI/CD pipeline timeout.
• Generate safe rollback SQL for partial index migrations that cannot be run in a transaction.
• Audit the consistency between the codebase migration files and the actual database schema state.

Known limitations

Requires manual provision of Postgres catalog data or access to the database environment. Does not execute commands directly; it provides marked recommendations for operator approval.