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4366f7fb3b
It does not give significant benefit, but now, you hashed/sparse_hashed dictionaries can be filled in parallel (#40003), using sharded dictionaries, and this should be used instead of PREALLOCATE. Note, that dictionaries, that had been created with PREALLOCATE will work, but simply ignore this attribute. Fixes: #41985 (cc @alexey-milovidov) Reverts: #23979 (cc @kitaisreal) Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
41 lines
1.2 KiB
Bash
Executable File
41 lines
1.2 KiB
Bash
Executable File
#!/usr/bin/env bash
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CUR_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
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# shellcheck source=../shell_config.sh
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. "$CUR_DIR"/../shell_config.sh
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# In [1] PREALLOCATE attribute had been added for HASHED dictionaries,
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# but it had been removed in [2].
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#
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# [1]: https://github.com/ClickHouse/ClickHouse/pull/23979
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# [2]: https://github.com/ClickHouse/ClickHouse/pull/45388
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#
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# This is a backward compatiblity test that you can create dictionary with
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# PREALLOCATE attribute (and also for the history/greppability, that it was
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# such).
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$CLICKHOUSE_CLIENT -nm -q "
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DROP TABLE IF EXISTS data_01509;
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DROP DICTIONARY IF EXISTS dict_01509;
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CREATE TABLE data_01509
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(
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key UInt64,
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value String
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)
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ENGINE = MergeTree()
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ORDER BY key;
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INSERT INTO data_01509 SELECT number key, toString(number) value FROM numbers(10e3);
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CREATE DICTIONARY dict_01509
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(
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key UInt64,
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value String DEFAULT '-'
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)
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PRIMARY KEY key
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SOURCE(CLICKHOUSE(HOST 'localhost' PORT tcpPort() TABLE 'data_01509'))
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LAYOUT(SPARSE_HASHED(PREALLOCATE 1))
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LIFETIME(0);
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SYSTEM RELOAD DICTIONARY dict_01509;
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" |& grep -o "HashedDictionary: .*"
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