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Merge pull request #59784 from ClickHouse/docs-cloud-values-query-complexity

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[Docs] Add cloud default values for query complexity
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Alexey Milovidov 2024-02-09 18:06:39 +01:00 committed by GitHub
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docs/en/operations/settings/query-complexity.md
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@ -28,6 +28,8 @@ The maximum amount of RAM to use for running a query on a single server.
The default setting is unlimited (set to `0`).
Cloud default value: depends on the amount of RAM on the replica.
The setting does not consider the volume of available memory or the total volume of memory on the machine.
The restriction applies to a single query within a single server.
You can use `SHOW PROCESSLIST` to see the current memory consumption for each query.
@ -104,7 +106,9 @@ Possible values:
- Maximum volume of RAM (in bytes) that can be used by the single [GROUP BY](../../sql-reference/statements/select/group-by.md#select-group-by-clause) operation.
- 0 — `GROUP BY` in external memory disabled.
Default value: 0.
Default value: `0`.
Cloud default value: half the memory amount per replica.
## max_bytes_before_external_sort {#settings-max_bytes_before_external_sort}
@ -115,6 +119,8 @@ Enables or disables execution of `ORDER BY` clauses in external memory. See [ORD
Default value: 0.
Cloud default value: half the memory amount per replica.
## max_rows_to_sort {#max-rows-to-sort}
A maximum number of rows before sorting. This allows you to limit memory consumption when sorting.
@ -129,7 +135,11 @@ What to do if the number of rows received before sorting exceeds one of the limi
## max_result_rows {#setting-max_result_rows}
Limit on the number of rows in the result. Also checked for subqueries, and on remote servers when running parts of a distributed query.
Limit on the number of rows in the result. Also checked for subqueries, and on remote servers when running parts of a distributed query. No limit is applied when value is `0`.
Default value: `0`.
Cloud default value: `0`.
## max_result_bytes {#max-result-bytes}
@ -137,10 +147,14 @@ Limit on the number of bytes in the result. The same as the previous setting.
## result_overflow_mode {#result-overflow-mode}
What to do if the volume of the result exceeds one of the limits: ‘throw’ or ‘break’. By default, throw.
What to do if the volume of the result exceeds one of the limits: ‘throw’ or ‘break’.
Using ‘break’ is similar to using LIMIT. `Break` interrupts execution only at the block level. This means that amount of returned rows is greater than [max_result_rows](#setting-max_result_rows), multiple of [max_block_size](../../operations/settings/settings.md#setting-max_block_size) and depends on [max_threads](../../operations/settings/settings.md#max_threads).
Default value: `throw`.
Cloud default value: `throw`.
Example:
``` sql