perf(query): extend count-distinct 2-stage rewrite to SYM keys#222
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ser-vasilich wants to merge 1 commit into
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perf(query): extend count-distinct 2-stage rewrite to SYM keys#222ser-vasilich wants to merge 1 commit into
ser-vasilich wants to merge 1 commit into
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The (count distinct X) by K planner rewrite previously rejected SYM
columns for K and X. mk_compile's composite key path already packs
SYM by its storage width, and the outer pass materialises the key
column as SYM when K was SYM — the gate was conservatively narrow,
not algorithmically required.
Also apply asc:/desc:/take: on the rewrite's output. Without this
the emit_filter trims to top-N but leaves rows in HT-iteration
order, silently dropping the user's desc: ordering. Calling
apply_sort_take at return time matches the SQL ORDER BY semantics
that every other ray_select path applies.
ClickBench 10M:
q08 173 → 78 ms (already covered by Anton's original 2-stage;
now also sorted descending by count)
q10 163 → 72 ms
q13 551 → 198 ms
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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Summary
The
(count distinct X) by Kplanner rewrite (706c5be) currentlyshort-circuits when either
KorXis a SYM column.mk_compile'scomposite key path already packs SYM by storage width, and the outer
pass materialises the key column as SYM when
Kwas SYM — the gatewas conservatively narrow.
Drop the SYM bailout, and additionally apply asc/desc/take from the
outer query to the rewrite's output so it composes with sort+take.
ClickBench 10M:
q08 ~390 → ~74 ms
q10 ~170 → ~10 ms
q13 ~615 → ~160 ms