RS-INDEX-010 — CREATE UNIQUE INDEX without proven uniqueness
Namespace: RS-INDEX · Code: RS-INDEX-010
A unique index can only build if the indexed set is actually unique. Uniqueness is never inferred from a sample (INV-UNIQUENESS): unproven uniqueness cannot certify PASS, and proven duplicates make the build fail. A PARTIAL index (WHERE …) or an EXPRESSION index (lower(email)) is a special case: the fixture records uniqueness for the whole column, which describes neither the predicate-selected subset nor the expression, so rowshape declines to decide in either direction and warns instead — duplicates in soft-deleted rows do not stop a WHERE deleted_at IS NULL index from building.
Remediation
Section titled “Remediation”Prove uniqueness before creating the unique index. If duplicates already exist, de-duplicate the column first (remove or merge the duplicate rows).
References
Section titled “References”- RFC §6.5
- RFC §7.2
- PRD §10
This page is generated from the same catalog rowshape explain RS-INDEX-010 reads, so the remediation here is byte-identical to the one a verdict carries — they cannot drift. An agent can read it with the explain_finding MCP tool.