Practical: Implement Row-Level Security Filtering

Problem

Given a set of RLS-style policies (predicates per role) and a query, return only the rows a given user may see — Supabase's Postgres RLS model.

Example

policy: user sees own rows -> filter where row.owner = user.id

Constraints

• Multiple policies combine (OR/AND)

What Supabase looks for

Postgres-grounded: understand how RLS policies filter rows and combine. Build the predicate evaluation.