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11 lines
481 B
SQL
11 lines
481 B
SQL
drop table if exists tab;
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create table tab (a UInt32, b UInt32) engine = MergeTree order by b % 2 sample by b % 2;
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insert into tab values (1, 2), (1, 4);
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select a from tab sample 1 / 2 prewhere b = 2;
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drop table if exists tab;
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DROP TABLE IF EXISTS sample_prewhere;
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CREATE TABLE sample_prewhere (CounterID UInt32, UserID UInt64) ENGINE = MergeTree ORDER BY UserID SAMPLE BY UserID;
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SELECT count() FROM sample_prewhere SAMPLE 1/2 PREWHERE CounterID = 1;
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DROP TABLE sample_prewhere;
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