gistfile1.txt

--- MySQL 9.7.0 with the z12a config (hypergraph optimizer disabled)

explain SELECT DISTINCT c FROM sbtest1 WHERE id BETWEEN 28428495 AND 28429494 ORDER BY c
  -> Sort: sbtest1.c
    -> Table scan on <temporary>  (cost=794..820 rows=1838)
        -> Temporary table with deduplication  (cost=794..794 rows=1838)
            -> Filter: (sbtest1.id between 28428495 and 28429494)  (cost=371 rows=1838)
                -> Index range scan on sbtest1 using PRIMARY over (28428495 <= id <= 28429494)  (cost=371 rows=1838)
                
--- MySQL 9.7.0 with the z12b config (hypergraph optimizer enabled)

explain SELECT DISTINCT c FROM sbtest1 WHERE id BETWEEN 41462615 AND 41463614 ORDER BY c
  -> Sort with duplicate removal: sbtest1.c  (cost=2797..2797 rows=1838)
    -> Filter: (sbtest1.id between 41462615 and 41463614)  (cost=0.826..1519 rows=1838)
        -> Index range scan on sbtest1 using PRIMARY over (41462615 <= id <= 41463614)  (cost=0.769..1413 rows=1838)