Manager Lookup

Employee rows can match manager rows.

highlighted = computed this step

A manager lookup reads the employee row on the left and the manager row on the right.

\text{employee manager lookup}

Read manager rows

3 employees find manager rows, producing 3 output rows.

\text{manager rows}=3

Self-join examples are tiny finite-table transforms with two aliases of one source table; SQL dialect completeness, type coercion, optimizer behavior, execution cost, indexing, and database-product claims are out of scope.

NULL has no manager

The row with a NULL manager key does not match any manager row.

\text{NULL does not match}

Summary

This is a finite lookup, not an org-chart product claim.

\text{scoped lookup}