Set Operations

Honest by Construction

Expected set facts are assertions only; compiler output is the source of truth.

highlighted = computed this step

Reject schema mismatches

Set operations need the same columns in the same order in this scoped model.

same schema order required\text{same schema order required}

Fail closed

The request is rejected, and result rows are 0.

result rows=0\text{result rows}=0

Set-operation examples are tiny finite bag transforms; SQL dialect details, type coercion, collations, ordering clauses, performance, and product behavior are out of scope.

Reject schema mismatches: left input bagidtag1red1red2blue3green Reject schema mismatches: right input bagtagidred1 bag countsrowleftCountrightCountresultCount[1, red]200[2, blue]100[3, green]100[red, 1]010 result rowsidtagnonenone set operation factsfactvalueopunionleftRowCount4rightRowCount1resultRowCount0distinctResultRows0rejectedyesrejectionReasonschema_order_mismatchrowOrdercanonical

Try to tamper

Wrong expected facts, derived sidecars, duplicate columns, unsupported operations, bools, and floats fail closed.

fail closed before render\text{fail closed before render}

Summary

Expected set-operation facts are assertions only; compiler output is the source of truth.

honest set facts\text{honest set facts}