WHERE Filters

FALSE Rows Are Dropped

WHERE drops rows whose predicate is FALSE.

highlighted = computed this step

FALSE rows are dropped

A row with a FALSE predicate result does not appear in the WHERE output.

drop FALSE\text{drop FALSE}

Read false rows

The predicate is FALSE for 1 row, and the filter drops 2 rows total.

FALSE rows=1\text{FALSE rows}=1

WHERE-filter examples are tiny finite-table transforms with SQL-style TRUE/FALSE/UNKNOWN logic; SQL dialect completeness, type coercion, optimizer behavior, indexing, and product claims are out of scope.

FALSE rows are dropped: base rowsitemqtystatuspen3opennotebook0openmug2closedstickerNULLopen predicate evaluationsourcevaluestruthkept0[pen, 3, open]TRUEyes1[notebook, 0, open]FALSEno2[mug, 2, closed]TRUEyes3[sticker, NULL, open]UNKNOWNno WHERE output rowsitemqtystatuspen3openmug2closed WHERE factsfactvalueinputRowCount4trueRows2falseRows1unknownRows1keptRows2droppedRows2rowOrdersource_orderunknownKeptno

Find notebook

The notebook row has qty equal to zero, so it fails qty greater than zero and is not in the output table.

FALSE means dropped\text{FALSE means dropped}

Summary

FALSE rows are not padded or marked; they are absent from the result.

absent from output\text{absent from output}