ClickHouse/dbms/tests/queries/0_stateless/00578_merge_table_sampling.sql

DROP TABLE IF EXISTS numbers1;
DROP TABLE IF EXISTS numbers2;

CREATE TABLE numbers1 ENGINE = Memory AS SELECT number FROM numbers(1000);
CREATE TABLE numbers2 ENGINE = Memory AS SELECT number FROM numbers(1000);

SELECT * FROM merge(currentDatabase(), '^numbers\\d+$') SAMPLE 0.1; -- { serverError 141 }

DROP TABLE numbers1;
DROP TABLE numbers2;

CREATE TABLE numbers1 ENGINE = MergeTree ORDER BY intHash32(number) SAMPLE BY intHash32(number) AS SELECT number FROM numbers(1000);
CREATE TABLE numbers2 ENGINE = MergeTree ORDER BY intHash32(number) SAMPLE BY intHash32(number) AS SELECT number FROM numbers(1000);

SELECT * FROM merge(currentDatabase(), '^numbers\\d+$') SAMPLE 0.01;

DROP TABLE numbers1;
DROP TABLE numbers2;