Optimizer Choices

Not a Speed Claim

Estimate choices are not benchmark results.

highlighted = computed this step

Not a speed claim

A different selectivity can choose a different plan inside the same toy model.

estimates can change\text{estimates can change}

Compare two estimates

One estimate chooses hash_join; the more selective estimate chooses nested_loop_join.

choice is model output\text{choice is model output}

Optimizer-choice examples are named toy estimate-model outputs; they are not benchmark results, database-product claims, hardware claims, or real speed predictions.

Not a speed claim: table statstablerolerowCountdistinctKeysOrdersleft_after_filter_input126Customersright_join_input88 filter estimatelabelinputRowsselectivityestimatedRowsstatus filter121/43 plan estimate rowsplanformulaleft/buildright/probeestimatedWorkchosennested_loop_joinfiltered_left_rows * right_rows3824nohash_joinbuild_rows + probe_rows8311yes estimate factsfactvaluemodelNametoy_optimizer_estimate_v1leftRows12rightRows8selectivity1/4filteredRows3nestedLoopWork24hashJoinWork11chosenPlanhash_joinrealSpeedClaimnoproductClaimnorequiresBenchmarkForSpeedyes
Not a speed claim: table statstablerolerowCountdistinctKeysOrdersleft_after_filter_input126Customersright_join_input88 filter estimatelabelinputRowsselectivityestimatedRowsstatus filter121/121 plan estimate rowsplanformulaleft/buildright/probeestimatedWorkchosennested_loop_joinfiltered_left_rows * right_rows188yeshash_joinbuild_rows + probe_rows819no estimate factsfactvaluemodelNametoy_optimizer_estimate_v1leftRows12rightRows8selectivity1/12filteredRows1nestedLoopWork8hashJoinWork9chosenPlannested_loop_joinrealSpeedClaimnoproductClaimnorequiresBenchmarkForSpeedyes

Keep the honesty note

The shown choice is an estimate-model output, not proof of real speed.

not a benchmark\text{not a benchmark}

Summary

Real speed would need a benchmark outside this static lesson.

benchmark required\text{benchmark required}