Fix materialized view dependency ordering - alphabetical sort breaks schema loads

[tesote-dfranco]

Problem

better_structure_sql sorts materialized views (and regular views) alphabetically when dumping db/schema/. This breaks when one view depends on another that sorts later alphabetically — loading the schema fails:

ERROR: relation "reconciliation_daily_summaries" does not exist

Real-world example: reconciliation_account_summaries depends on reconciliation_daily_summaries, but sorts first alphabetically, so the CREATE statement comes before its dependency exists.

Even when IF NOT EXISTS prevents hard failures, every db:migrate can flip the order, creating noisy diffs in PRs.

Root Cause

File: lib/better_structure_sql/adapters/postgresql_adapter.rb

• Line ~190: ORDER BY matviewname — alphabetical, ignores dependencies
• Line ~165: ORDER BY viewname — same issue for regular views

The gem already has a DependencyResolver class (lib/better_structure_sql/dependency_resolver.rb) with topological sorting. It just isn't wired into the view/materialized view fetching pipeline.

Reproduction Steps

1. Create a PostgreSQL database with two materialized views where one depends on the other
2. Name them such that the dependent view sorts alphabetically before its dependency
   • Example: reconciliation_account_summaries depends on reconciliation_daily_summaries
3. Run better_structure_sql to dump the schema
4. Try to reload the schema:

   psql -f db/schema.sql

5. Result: ERROR: relation "reconciliation_daily_summaries" does not exist

Proposed Solution

Query PostgreSQL's pg_depend + pg_rewrite catalogs to discover inter-view dependencies, then feed results into the existing DependencyResolver for topological sorting.

Steps:

1. Add sort_by_dependencies(connection, objects, relkind) helper method that queries dependencies
2. Update fetch_materialized_views to remove ORDER BY matviewname and apply sort_by_dependencies instead
3. Update fetch_views to remove ORDER BY viewname and apply sort_by_dependencies instead
4. Add RSpec tests for dependency ordering scenarios (matview→matview, view→view, circular dependencies, no dependencies)

Related Files

• lib/better_structure_sql/adapters/postgresql_adapter.rb - where changes are needed
• lib/better_structure_sql/dependency_resolver.rb - existing class with topological sorting