A Redshift fact table is queried almost exclusively by date ranges (WHERE event_date BETWEEN ...). Which design makes those scans cheapest?
A.DISTKEY on event_date
DISTKEY is for join colocation — not range filtering.
B.Sort key on event_date — zone maps let Redshift skip whole blocks outside the range
Correct. Sort key + zone maps = massive scan pruning.
C.More nodes
Bigger cluster brute-forces a design problem.
D.A materialized view over the raw table
MVs precompute specific queries — not a general fix.
Why this answer
Sort keys physically order table blocks — Redshift's zone maps (min/max per block) then skip irrelevant blocks, so range predicates touch a fraction of the table. DISTKEY controls distribution for joins, not scan selectivity.
Correct answer: B · Last reviewed 2026-11-04
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