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join_algorithm setting
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@ -509,6 +509,19 @@ Possible values:
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Default value: `ALL`.
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## join_algorithm {#settings-join_algorithm}
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Specifies [JOIN](../../sql-reference/statements/select/join.md) algorithm.
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Possible values:
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- 'hash'
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- 'partial_merge'
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- 'prefer_partial_merge'
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- 'auto' — tries to change `hash` join to `merge` join on the fly to avoid out of memory.
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Default value: `hash`.
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## join_any_take_last_row {#settings-join_any_take_last_row}
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Changes behaviour of join operations with `ANY` strictness.
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@ -36,12 +36,21 @@ Additional join types available in ClickHouse:
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- `LEFT ANY JOIN`, `RIGHT ANY JOIN` and `INNER ANY JOIN`, partially (for opposite side of `LEFT` and `RIGHT`) or completely (for `INNER` and `FULL`) disables the cartesian product for standard `JOIN` types.
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- `ASOF JOIN` and `LEFT ASOF JOIN`, joining sequences with a non-exact match. `ASOF JOIN` usage is described below.
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## Setting {#join-settings}
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## Settings {#join-settings}
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!!! note "Note"
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The default join type can be overriden using [join_default_strictness](../../../operations/settings/settings.md#settings-join_default_strictness) setting.
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The default join type can be overriden using [join_default_strictness](../../../operations/settings/settings.md#settings-join_default_strictness) setting.
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Also the behavior of ClickHouse server for `ANY JOIN` operations depends on the [any_join_distinct_right_table_keys](../../../operations/settings/settings.md#any_join_distinct_right_table_keys) setting.
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The behavior of ClickHouse server for `ANY JOIN` operations depends on the [any_join_distinct_right_table_keys](../../../operations/settings/settings.md#any_join_distinct_right_table_keys) setting.
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**See also**
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- [join_algorithm](../../../operations/settings/settings.md#settings-join_algorithm)
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- [join_any_take_last_row](../../../operations/settings/settings.md#settings-join_any_take_last_row)
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- [join_use_nulls](../../../operations/settings/settings.md#join_use_nulls)
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- [partial_merge_join_optimizations](../../../operations/settings/settings.md#partial_merge_join_optimizations)
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- [partial_merge_join_rows_in_right_blocks](../../../operations/settings/settings.md#partial_merge_join_rows_in_right_blocks)
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- [join_on_disk_max_files_to_merge](../../../operations/settings/settings.md#join_on_disk_max_files_to_merge)
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- [any_join_distinct_right_table_keys](../../../operations/settings/settings.md#any_join_distinct_right_table_keys)
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### ASOF JOIN Usage {#asof-join-usage}
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@ -490,6 +490,19 @@ ClickHouse может парсить только базовый формат `Y
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Значение по умолчанию: `ALL`.
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## join_algorithm {#settings-join_algorithm}
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Определяет алгоритм выполнения запроса [JOIN](../../sql-reference/statements/select/join.md).
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Возможные значения:
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- 'hash'
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- 'partial_merge'
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- 'prefer_partial_merge'
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- 'auto' — сервер пытается на лету заменить алгоритм `hash` на `merge` чтобы избежать переполнения памяти.
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Значение по умолчанию: `hash`.
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## join_any_take_last_row {#settings-join_any_take_last_row}
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Изменяет поведение операций, выполняемых со строгостью `ANY`.
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@ -38,11 +38,20 @@ FROM <left_table>
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## Настройки {#join-settings}
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!!! note "Примечание"
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Значение строгости по умолчанию может быть переопределено с помощью настройки [join_default_strictness](../../../operations/settings/settings.md#settings-join_default_strictness).
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Значение строгости по умолчанию может быть переопределено с помощью настройки [join_default_strictness](../../../operations/settings/settings.md#settings-join_default_strictness).
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Поведение сервера ClickHouse для операций `ANY JOIN` зависит от параметра [any_join_distinct_right_table_keys](../../../operations/settings/settings.md#any_join_distinct_right_table_keys).
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**См. также**
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- [join_algorithm](../../../operations/settings/settings.md#settings-join_algorithm)
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- [join_any_take_last_row](../../../operations/settings/settings.md#settings-join_any_take_last_row)
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- [join_use_nulls](../../../operations/settings/settings.md#join_use_nulls)
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- [partial_merge_join_optimizations](../../../operations/settings/settings.md#partial_merge_join_optimizations)
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- [partial_merge_join_rows_in_right_blocks](../../../operations/settings/settings.md#partial_merge_join_rows_in_right_blocks)
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- [join_on_disk_max_files_to_merge](../../../operations/settings/settings.md#join_on_disk_max_files_to_merge)
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- [any_join_distinct_right_table_keys](../../../operations/settings/settings.md#any_join_distinct_right_table_keys)
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### Использование ASOF JOIN {#asof-join-usage}
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`ASOF JOIN` применим в том случае, когда необходимо объединять записи, которые не имеют точного совпадения.
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