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34 lines
1.2 KiB
SQL
34 lines
1.2 KiB
SQL
-- Tags: no-backward-compatibility-check
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SET mutations_sync = 2;
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DROP TABLE IF EXISTS t_sparse_alter;
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CREATE TABLE t_sparse_alter (id UInt64, u UInt64, s String)
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ENGINE = MergeTree ORDER BY id
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SETTINGS ratio_of_defaults_for_sparse_serialization = 0.5;
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INSERT INTO t_sparse_alter SELECT
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number,
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if (number % 11 = 0, number, 0),
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if (number % 13 = 0, toString(number), '')
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FROM numbers(2000);
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SELECT column, serialization_kind FROM system.parts_columns WHERE database = currentDatabase() AND table = 't_sparse_alter' AND active ORDER BY column;
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SELECT uniqExact(u), uniqExact(s) FROM t_sparse_alter;
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ALTER TABLE t_sparse_alter DROP COLUMN s, RENAME COLUMN u TO t;
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ALTER TABLE t_sparse_alter MODIFY COLUMN t UInt16;
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SELECT column, serialization_kind FROM system.parts_columns WHERE database = currentDatabase() AND table = 't_sparse_alter' AND active ORDER BY column;
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SELECT uniqExact(t) FROM t_sparse_alter;
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DETACH TABLE t_sparse_alter;
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ATTACH TABLE t_sparse_alter;
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SELECT column, serialization_kind FROM system.parts_columns WHERE database = currentDatabase() AND table = 't_sparse_alter' AND active ORDER BY column;
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SELECT uniqExact(t) FROM t_sparse_alter;
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DROP TABLE t_sparse_alter;
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