WHERE vs HAVING

Honest by Construction

Expected row and group filter facts are assertions only.

highlighted = computed this step

Honest by construction

Expected WHERE and HAVING facts are assertions only.

compiler is source of truth\text{compiler is source of truth}

Render checked output

The guarded pipeline renders 1 output group after recomputation.

checked groups=1\text{checked groups}=1

HAVING examples are tiny finite group-filter transforms; SQL dialect completeness, optimizer behavior, indexing, and product claims are out of scope.

Honest by construction: base rowsidregionstatusqty1eastopen22eastopen33westopen14westclosed45northNULL26northopen1 WHERE before groupingsourceinputwhereTruthgroupedRole0[1, east, open, 2]TRUEgrouped1[2, east, open, 3]TRUEgrouped2[3, west, open, 1]TRUEgrouped3[4, west, closed, 4]FALSEdropped_before_grouping4[5, north, NULL, 2]UNKNOWNdropped_before_grouping5[6, north, open, 1]TRUEgrouped GROUP BY bucketskeysourceRowsrowCount[east][0, 1]2[west][2]1[north][5]1 Aggregate facts per groupkeysourceRowsaggregates[east][0, 1]{n:2, total_qty:5}[west][2]{n:1, total_qty:1}[north][5]{n:1, total_qty:1} HAVING result per groupkeypredicatetruthoutputRole[east]total_qty ge 2TRUEkept[west]total_qty ge 2FALSEdropped[north]total_qty ge 2FALSEdropped HAVING output groupsregionntotal_qtyeast25 HAVING factsfactvalueinputRowCount6whereKeptRows4whereDroppedRows2groupCount3aggregateCount2outputGroupCount1havingTrueCount1havingFalseCount2havingUnknownCount0groupOrderfirst_seen_after_wherepipelineWHERE_before_GROUP_BY_then_HAVING

Try to tamper

Wrong expected facts, derived sidecars, missing columns, missing aggregate aliases, bools, and floats fail closed.

tamper rejected\text{tamper rejected}

Summary

This book shows exact finite WHERE before GROUP BY and HAVING after aggregates only.

scoped row and group filters\text{scoped row and group filters}