# Data Model: PostgreSQL Database Replacement

> For the complete documentation index, see [llms.txt](https://deploy-preview-472--lucky-concha-f3599f.netlify.app/llms.txt).

## Scope

State `005` keeps the same business entities as prior states and changes database engine/runtime from H2 to PostgreSQL.

## Entity Impact

*   Added: none
*   Changed: physical schema implementation details to PostgreSQL-compatible DDL/types
*   Removed: dependency on H2-specific runtime assumptions

## Notes

Data model semantics are intentionally preserved. This is a persistence-engine substitution state, not a functional domain redesign.