geointel/skills/postgis-migration/SKILL.md

Skill: PostGIS Migration

Use this skill when creating database models, migrations, geometry storage or spatial indexes.

Read first

• docs/DATABASE_SCHEMA.md
• docs/DATABASE_IMPLEMENTATION_PLAN.md
• docs/standards/GIS_STANDARDS.md
• docs/specs/STATE_MACHINES.md
• relevant ADRs

Spatial rules

• PostgreSQL + PostGIS is mandatory.
• Store canonical geometry in PostGIS geometry columns.
• Preserve original CRS metadata on datasets.
• Normalize internal spatial operations according to GIS standards.
• Create spatial indexes for queryable geometries.
• Use explicit units for area, distance and length.

Migration checklist

• Add model.
• Add migration.
• Add indexes.
• Add constraints.
• Add state enum where required.
• Add rollback-safe migration where practical.
• Add fixture/test coverage for geometry roundtrip.

Forbidden shortcuts

• No geometry as unvalidated plain text for canonical records.
• No silent CRS assumptions.
• No schema drift from docs without updating the contract.

Completion report fields

• Tables changed.
• Geometry columns added.
• Indexes added.
• Migration commands run.
• Compatibility risks.