Cypher: relationship alias unsupported in row expression select (blocks IC11 job-referral)

[lmeyerov]

Summary

When an IC11-style Cypher query uses a relationship alias (e.g. workAt) in a select row expression, the engine raises an unsupported-token error. This blocks execution of LDBC SNB Interactive Complex Query 11 (IC11 — job-referral).

Error

[invalid-node-reference] Error executing 'select': unsupported token in row expression: 'workAt' | field: function | value: 'select'

Failing Pattern

IC11 matches a friend-of-friend to a company via a WORKS_AT relationship and then projects properties from both the relationship (workAt) and the company node:

MATCH (p:Person {id: $personId})-[:KNOWS*1..2]-(friend:Person),
      (friend)-[workAt:WORKS_AT]->(company:Company)
WHERE workAt.workFrom < $workFromYear
  AND (company)-[:IS_LOCATED_IN]->(:Place {name: $countryName})
RETURN friend.id, friend.firstName, friend.lastName,
       company.name AS organizationName,
       workAt.workFrom AS organizationWorkFromYear
ORDER BY organizationWorkFromYear ASC, friend.lastName ASC, friend.id ASC
LIMIT 10

The workAt relationship alias appears in the RETURN projection, and the engine's select row expression evaluator does not handle relationship aliases — only node aliases are supported.

Relationship to Related Issues

• AST row select cannot reference edge alias properties after traversal #982 (closed) tracked edge alias properties after traversal in GFQL AST. The current gap is specifically in the Cypher select row expression path, not the GFQL AST path.
• This is a new, untracked gap in the Cypher lowering layer.

Affected Queries

• LDBC SNB Interactive Complex 11 (interactive-complex-11.cypher) — job-referral primitive
• Any Cypher query that projects a relationship alias property in RETURN (e.g. workAt.workFrom)

Provenance

Measured and reported from the pyg-bench SNB Interactive conformance harness.