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12 lines
490 B
SQL
12 lines
490 B
SQL
set allow_experimental_projection_optimization = 1, force_optimize_projection = 1;
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drop table if exists tp;
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create table tp (type Int32, device UUID, cnt UInt64) engine = MergeTree order by (type, device);
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insert into tp select number%3, generateUUIDv4(), 1 from numbers(300);
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alter table tp add projection uniq_city_proj ( select type, uniq(cityHash64(device)), sum(cnt) group by type );
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alter table tp materialize projection uniq_city_proj settings mutations_sync = 1;
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drop table tp;
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