\ Source-Level Filtering (also known as Partial Evaluation) is where the PDP returns a query basis (e.g., SQL) that is sent or appended to an existing query and sent to the database (1) . This capability exists in Open Policy Agent (OPA) under the

compile

API and is already available within Permit's PDP . According to the documentation, there's also a Simplified Partial-evaluation feature in advanced stages of release, which includes built-in translation to SQL . For implementing partial evaluation with OPA/Rego policies, the approach involves compiling policy rules into conditional expressions like SQL

WHERE

clauses (2) . Through partial evaluation, a policy might compile to a SQL clause that can be appended to your database queries . Some tools, including Permit, fully support partial evaluation via OPA's AST (Abstract Syntax Tree) functions, leveraging OPA's native capability for AST compilation during partial evaluation . Additionally, Permit offers early access support for Postgres partial evaluation, enabling policy rules to be directly converted into SQL queries without requiring manual Rego or policy compilation . To help our engineers investigate your specific implementation needs: 1. Which Workspace / Project / Env are you using? 2. What calls are you performing (as SDK code or CURL) ? 3. Which PDP version are you running? 4. Could you share relevant logs from your PDP?

To learn more, see the sources I considered: [[1] Data Filtering](https://docs.permit.io/how-to/enforce-permissions/data-filtering) [[2] Implementing Database Permissions](https://www.permit.io/blog/why-data-filtering-matters-for-database-authorization)