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Speed up `set` index by adding comparison with min-max values #64134

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nickitat opened this issue May 20, 2024 · 1 comment

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easy task performance

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nickitat commented May 20, 2024 •

edited

BTW, once I noticed that set is 4 times slower than minmax with the same data.

set max_threads=1;

create table ind_minmax(A Int64, B Int64, index x1 B type minmax granularity 1) 
Engine MergeTree order by A as select number, cityHash64(number)%111111=1 from numbers(1e8);
optimize table ind_minmax final;

create table ind_set(A Int64, B Int64, index x1 B type set(2) granularity 1) 
Engine MergeTree order by A as select number, cityHash64(number)%111111=1 from numbers(1e8);
optimize table ind_set final;

select count() from ind_minmax where B = 1;
Elapsed: 0.015 sec. Processed 7.26 million rows

select count() from ind_set where B = 1;
Elapsed: 0.060 sec. Processed 7.26 million rows

drop table ind_set;
drop table ind_minmax;