Managed Service for ClickHouse API, gRPC: UserService.GrantPermission

Field

Description

cluster_id

string

Required field. ID of the ClickHouse cluster the user belongs to.
To get the cluster ID, use a ClusterService.List request.

user_name

string

Required field. Name of the user to grant the permission to.
To get the name of the user, use a UserService.List request.

permission

Permission

Permission that should be granted to the specified user.

Field

Description

database_name

string

Name of the database that the permission grants access to.

Field

Description

id

string

ID of the operation.

description

string

Description of the operation. 0-256 characters long.

created_at

google.protobuf.Timestamp

Creation timestamp.

created_by

string

ID of the user or service account who initiated the operation.

modified_at

google.protobuf.Timestamp

The time when the Operation resource was last modified.

done

bool

If the value is false, it means the operation is still in progress.
If true, the operation is completed, and either error or response is available.

metadata

GrantUserPermissionMetadata

Service-specific metadata associated with the operation.
It typically contains the ID of the target resource that the operation is performed on.
Any method that returns a long-running operation should document the metadata type, if any.

error

google.rpc.Status

The error result of the operation in case of failure or cancellation.

Includes only one of the fields error, response.

The operation result.
If done == false and there was no failure detected, neither error nor response is set.
If done == false and there was a failure detected, error is set.
If done == true, exactly one of error or response is set.

response

User

The normal response of the operation in case of success.
If the original method returns no data on success, such as Delete,
the response is google.protobuf.Empty.
If the original method is the standard Create/Update,
the response should be the target resource of the operation.
Any method that returns a long-running operation should document the response type, if any.

Includes only one of the fields error, response.

The operation result.
If done == false and there was no failure detected, neither error nor response is set.
If done == false and there was a failure detected, error is set.
If done == true, exactly one of error or response is set.

Field

Description

cluster_id

string

ID of the ClickHouse cluster the user belongs to.

user_name

string

Name of the user that is being granted a permission.

Field

Description

name

string

Name of the ClickHouse user.

cluster_id

string

ID of the ClickHouse cluster the user belongs to.

permissions[]

Permission

Set of permissions granted to the user.

settings

UserSettings

quotas[]

UserQuota

Set of quotas assigned to the user.

Field

Description

database_name

string

Name of the database that the permission grants access to.

Field

Description

readonly

google.protobuf.Int64Value

Restricts permissions for non-DDL queries. To restrict permissions for DDL queries, use allow_ddl instead.

• 0 (default)-no restrictions.
• 1-only read data queries are allowed.
• 2-read data and change settings queries are allowed.

See in-depth description in ClickHouse documentation.

allow_ddl

google.protobuf.BoolValue

Determines whether DDL queries are allowed (e.g., CREATE, ALTER, RENAME, etc).

Default value: true.

See in-depth description in ClickHouse documentation.

allow_introspection_functions

google.protobuf.BoolValue

Enables introspections functions for query profiling.

More info see in ClickHouse documentation.

connect_timeout

google.protobuf.Int64Value

Connection timeout in milliseconds.

Value must be greater than 0 (default: 10000, 10 seconds).

connect_timeout_with_failover

google.protobuf.Int64Value

The timeout in milliseconds for connecting to a remote server for a Distributed table engine. Applies only if the cluster uses sharding and replication. If unsuccessful, several attempts are made to connect to various replicas.

Default value: 50.

More info see in ClickHouse documentation.

receive_timeout

google.protobuf.Int64Value

Receive timeout in milliseconds.

Value must be greater than 0 (default: 300000, 300 seconds or 5 minutes).

send_timeout

google.protobuf.Int64Value

Send timeout in milliseconds.

Value must be greater than 0 (default: 300000, 300 seconds or 5 minutes).

timeout_before_checking_execution_speed

google.protobuf.Int64Value

Timeout (in seconds) between checks of execution speed. It is checked that execution speed is not less that specified in min_execution_speed parameter.

Default value: 10.

insert_quorum

google.protobuf.Int64Value

Enables or disables write quorum for ClickHouse cluster.
If the value is less than 2, then write quorum is disabled, otherwise it is enabled.

When used, write quorum guarantees that ClickHouse has written data to the quorum of insert_quorum replicas with no errors until the insert_quorum_timeout expires.
All replicas in the quorum are in the consistent state, meaning that they contain linearized data from the previous INSERT queries.
Employ write quorum, if you need the guarantees that the written data would not be lost in case of one or more replicas failure.

You can use select_sequential_consistency setting to read the data written with write quorum.

See in-depth description in ClickHouse documentation.

insert_quorum_timeout

google.protobuf.Int64Value

Quorum write timeout in milliseconds.

If the write quorum is enabled in the cluster, this timeout expires and some data is not written to the insert_quorum replicas, then ClickHouse will abort the execution of INSERT query and return an error.
In this case, the client must send the query again to write the data block into the same or another replica.

Minimum value: 1000, 1 second (default: 60000, 1 minute).

insert_quorum_parallel

google.protobuf.BoolValue

See in-depth description in ClickHouse documentation.

insert_null_as_default

google.protobuf.BoolValue

Enables the insertion of default values instead of NULL into columns with not nullable data type.

Default value: true.

More info see in ClickHouse documentation.

select_sequential_consistency

google.protobuf.BoolValue

Determines the behavior of SELECT queries from the replicated table: if enabled, ClickHouse will terminate a query with error message in case the replica does not have a chunk written with the quorum and will not read the parts that have not yet been written with the quorum.

Default value: false (sequential consistency is disabled).

deduplicate_blocks_in_dependent_materialized_views

google.protobuf.BoolValue

See in-depth description in ClickHouse documentation.

replication_alter_partitions_sync

google.protobuf.Int64Value

Wait mode for asynchronous actions in ALTER queries on replicated tables:

• 0-do not wait for replicas.
• 1-only wait for own execution (default).
• 2-wait for all replicas.

See in-depth description in ClickHouse documentation.

max_replica_delay_for_distributed_queries

google.protobuf.Int64Value

Max replica delay in milliseconds. If a replica lags more than the set value, this replica is not used and becomes a stale one.

Minimum value: 1000, 1 second (default: 300000, 300 seconds or 5 minutes).

See in-depth description in ClickHouse documentation.

fallback_to_stale_replicas_for_distributed_queries

google.protobuf.BoolValue

Enables or disables query forcing to a stale replica in case the actual data is unavailable.
If enabled, ClickHouse will choose the most up-to-date replica and force the query to use the data in this replica.
This setting can be used when doing SELECT query from a distributed table that points to replicated tables.

Default value: true (query forcing is enabled).

See in-depth description in ClickHouse documentation.

distributed_product_mode

enum DistributedProductMode

Determine the behavior of distributed subqueries.

See in-depth description in ClickHouse documentation.

• DISTRIBUTED_PRODUCT_MODE_UNSPECIFIED
• DISTRIBUTED_PRODUCT_MODE_DENY: Default value. Prohibits using these types of subqueries (returns the "Double-distributed in/JOIN subqueries is denied" exception).
• DISTRIBUTED_PRODUCT_MODE_LOCAL: Replaces the database and table in the subquery with local ones for the destination server (shard), leaving the normal IN/JOIN.
• DISTRIBUTED_PRODUCT_MODE_GLOBAL: Replaces the IN/JOIN query with GLOBAL IN/GLOBAL JOIN.
• DISTRIBUTED_PRODUCT_MODE_ALLOW: Allows the use of these types of subqueries.

distributed_aggregation_memory_efficient

google.protobuf.BoolValue

Enables of disables memory saving mode when doing distributed aggregation.

When ClickHouse works with a distributed query, external aggregation is done on remote servers.
Enable this setting to achieve a smaller memory footprint on the server that sourced such a distributed query.

Default value: false (memory saving mode is disabled).

See in-depth description in ClickHouse documentation.

distributed_ddl_task_timeout

google.protobuf.Int64Value

Timeout for DDL queries, in milliseconds.

skip_unavailable_shards

google.protobuf.BoolValue

Enables or disables silent skipping of unavailable shards.

A shard is considered unavailable if all its replicas are also unavailable.

Default value: false (silent skipping is disabled).

See in-depth description in ClickHouse documentation.

compile_expressions

google.protobuf.BoolValue

Enables or disables expression compilation.
If you execute a lot of queries that contain identical expressions, then enable this setting.
As a result, such queries may be executed faster due to use of compiled expressions.

Use this setting in combination with min_count_to_compile_expression setting.

Default value: false (expression compilation is disabled).

min_count_to_compile_expression

google.protobuf.Int64Value

How many identical expressions ClickHouse has to encounter before they are compiled.

Minimum value: 0 (default: 3).

For the 0 value compilation is synchronous: a query waits for expression compilation process to complete prior to continuing execution.
It is recommended to set this value only for testing purposes.

For all other values, compilation is asynchronous: the compilation process executes in a separate thread.
When a compiled expression is ready, it will be used by ClickHouse for eligible queries, including the ones that are currently running.

max_block_size

google.protobuf.Int64Value

The maximum block size for reading.

Data in ClickHouse is organized and processed by blocks (block is a set of columns' parts).
The internal processing cycles for a single block are efficient enough, but there are noticeable expenditures on each block.

This setting is a recommendation for size of block (in a count of rows) that should be loaded from tables.

Value must be greater than 0 (default: 65536).

See in-depth description in ClickHouse documentation.

min_insert_block_size_rows

google.protobuf.Int64Value

Limits the minimum number of rows in a block to be inserted in a table by INSERT query.
Blocks that are smaller than the specified value, will be squashed together into the bigger blocks.

Minimal value: 0, block squashing is disabled (default: 1048576).

min_insert_block_size_bytes

google.protobuf.Int64Value

Limits the minimum number of bytes in a block to be inserted in a table by INSERT query.
Blocks that are smaller than the specified value, will be squashed together into the bigger blocks.

Minimal value: 0, block squashing is disabled (default: 268435456, 256 MB).

max_insert_block_size

google.protobuf.Int64Value

Allows to form blocks of the specified size (in bytes) when inserting data in a table.
This setting has effect only if server is creating such blocks by itself.

Value must be greater than 0 (default: 1048576).

See in-depth description in ClickHouse documentation.

min_bytes_to_use_direct_io

google.protobuf.Int64Value

Limits the minimum number of bytes to enable unbuffered direct reads from disk (Direct I/O).

By default, ClickHouse does not read data directly from disk, but relies on the filesystem and its cache instead.
Such reading strategy is effective when the data volume is small.
If the amount of the data to read is huge, it is more effective to read directly from the disk, bypassing the filesystem cache.

If the total amount of the data to read is greater than the value of this setting, then ClickHouse will fetch this data directly from the disk.

Minimal value and default value: 0, Direct I/O is disabled.

use_uncompressed_cache

google.protobuf.BoolValue

Determines whether to use the cache of uncompressed blocks, or not.
Using this cache can significantly reduce latency and increase the throughput when a huge amount of small queries is to be processed.
Enable this setting for the users who instantiates small queries frequently.

This setting has effect only for tables of the MergeTree family.

Default value: false (uncompressed cache is disabled).

See in-depth description in ClickHouse documentation.

merge_tree_max_rows_to_use_cache

google.protobuf.Int64Value

Limits the maximum size in rows of the request that can use the cache of uncompressed data. The cache is not used for requests larger
than the specified value.

Use this setting in combination with use_uncompressed_cache setting.

Value must be greater than 0 (default: 128x8192).

merge_tree_max_bytes_to_use_cache

google.protobuf.Int64Value

Limits the maximum size in bytes of the request that can use the cache of uncompressed data. The cache is not used for requests larger
than the specified value.

Use this setting in combination with use_uncompressed_cache setting.

Value must be greater than 0 (default: 192x10x1024x1024).

merge_tree_min_rows_for_concurrent_read

google.protobuf.Int64Value

Limits the minimum number of rows to be read from a file to enable concurrent read.
If the number of rows to be read exceeds this value, then ClickHouse will try to use a few threads to read from a file concurrently.

This setting has effect only for tables of the MergeTree family.

Value must be greater than 0 (default: 20x8192).

merge_tree_min_bytes_for_concurrent_read

google.protobuf.Int64Value

Limits the number of bytes to be read from a file to enable concurrent read.
If the number of bytes to be read exceeds this value, then ClickHouse will try to use a few threads to read from a file concurrently.

This setting has effect only for tables of the MergeTree family.

Value must be greater than 0 (default: 24x10x1024x1024).

max_bytes_before_external_group_by

google.protobuf.Int64Value

Sets the threshold of RAM consumption (in bytes) after that the temporary data, collected during the GROUP BY operation, should be flushed to disk to limit the RAM comsumption.

By default, aggregation is done by employing hash table that resides in RAM.
A query can result in aggregation of huge data volumes that can lead to memory exhaustion and abortion of the query (see the max_memory_usage setting).
For such queries, you can use this setting to force ClickHouse to do flushing and complete aggregation successfully.

Minimal value and default value: 0, GROUP BY in the external memory is disabled.

When using aggregation in external memory, it is recommended to set the value of this setting twice as low as the max_memory_usage setting value (by default, the maximum memory usage is limited to ten gigabytes).

See in-depth description in ClickHouse documentation.

See also: the distributed_aggregation_memory_efficient setting.

max_bytes_before_external_sort

google.protobuf.Int64Value

This setting is equivalent of the max_bytes_before_external_group_by setting, except for it is for sort operation (ORDER BY), not aggregation.

group_by_two_level_threshold

google.protobuf.Int64Value

Sets the threshold of the number of keys, after that the two-level aggregation should be used.

Minimal value: 0, threshold is not set (default: 10000).

group_by_two_level_threshold_bytes

google.protobuf.Int64Value

Sets the threshold of the number of bytes, after that the two-level aggregation should be used.

Minimal value: 0, threshold is not set (default: 100000000).

priority

google.protobuf.Int64Value

Sets the priority of a query.

• 0-priority is not used.
• 1-the highest priority.
• and so on. The higher the number, the lower a query's priority.

This setting should be set up for each query individually.

If ClickHouse is working with the high-priority queries, and a low-priority query enters, then the low-priority query is paused until higher-priority queries are completed.

Minimal value and default value: 0, priority is not used.

max_threads

google.protobuf.Int64Value

Limits the maximum number of threads to process the request (setting does not take threads that read data from remote servers into account).

This setting applies to threads that perform the same stages of the query processing pipeline in parallel.

Minimal value and default value: 0 (the thread number is calculated automatically based on the number of physical CPU cores, no HyperThreading cores are taken into account).

See in-depth description in ClickHouse documentation.

max_memory_usage

google.protobuf.Int64Value

Limits the maximum memory usage (in bytes) for processing of a single user's query on a single server.
This setting does not take server's free RAM amount or total RAM amount into account.

This limitation is enforced for any user's single query on a single server.

Minimal value: 0, no limitation is set.
Value that is set in the ClickHouse default config file: 10737418240 (10 GB).

If you use max_bytes_before_external_group_by or max_bytes_before_external_sort setting, then it is recommended to set their values twice as low as max_memory_usage setting value.

See in-depth description in ClickHouse documentation.

max_memory_usage_for_user

google.protobuf.Int64Value

Limits the maximum memory usage (in bytes) for processing of user's queries on a single server.
This setting does not take server's free RAM amount or total RAM amount into account.

This limitation is enforced for all queries that belong to one user and run simultaneously on a single server.

Minimal value and default value: 0, no limitation is set.

max_network_bandwidth

google.protobuf.Int64Value

The maximum speed of data exchange over the network in bytes per second for a query.

Minimal value and default value: 0, no limitation is set.

max_network_bandwidth_for_user

google.protobuf.Int64Value

The maximum speed of data exchange over the network in bytes per second for all concurrently running user queries.

Minimal value and default value: 0, no limitation is set.

max_partitions_per_insert_block

google.protobuf.Int64Value

See in-depth description in ClickHouse documentation.

max_concurrent_queries_for_user

google.protobuf.Int64Value

The maximum number of concurrent requests per user.
Default value: 0 (no limit).

force_index_by_date

google.protobuf.BoolValue

If enabled, query is not executed if the ClickHouse can't use index by date.
This setting has effect only for tables of the MergeTree family.

Default value: false (setting is disabled, query executes even if ClickHouse can't use index by date).

See in-depth description in ClickHouse documentation.

force_primary_key

google.protobuf.BoolValue

If enabled, query is not executed if the ClickHouse can't use index by primary key.
This setting has effect only for tables of the MergeTree family.

Default value: false (setting is disabled, query executes even if ClickHouse can't use index by primary key).

See in-depth description in ClickHouse documentation.

max_rows_to_read

google.protobuf.Int64Value

Limits the maximum number of rows that can be read from a table when running a query.

Minimal value and default value: 0, no limitation is set.

See in-depth description in ClickHouse documentation.

max_bytes_to_read

google.protobuf.Int64Value

Limits the maximum number of bytes (uncompressed data) that can be read from a table when running a query.

Minimal value and default value: 0, no limitation is set.

read_overflow_mode

enum OverflowMode

Determines the behavior on exceeding limits while reading the data.

• throw-abort query execution, return an error.
• break-stop query execution, return partial result.

• OVERFLOW_MODE_UNSPECIFIED
• OVERFLOW_MODE_THROW
• OVERFLOW_MODE_BREAK

max_rows_to_group_by

google.protobuf.Int64Value

Limits the maximum number of unique keys received from aggregation function.
This setting helps to reduce RAM consumption while doing aggregation.

Minimal value and default value: 0, no limitation is set.

group_by_overflow_mode

enum GroupByOverflowMode

Determines the behavior on exceeding limits while doing aggregation.

• throw-abort query execution, return an error.
• break-stop query execution, return partial result.
• any-perform approximate GROUP BY operation by continuing aggregation for the keys that got into the set, but don't add new keys to the set.

• GROUP_BY_OVERFLOW_MODE_UNSPECIFIED
• GROUP_BY_OVERFLOW_MODE_THROW
• GROUP_BY_OVERFLOW_MODE_BREAK
• GROUP_BY_OVERFLOW_MODE_ANY

max_rows_to_sort

google.protobuf.Int64Value

Limits the maximum number of rows that can be read from a table for sorting.
This setting helps to reduce RAM consumption.

Minimal value and default value: 0, no limitation is set.

max_bytes_to_sort

google.protobuf.Int64Value

Limits the maximum number of bytes (uncompressed data) that can be read from a table for sorting.
This setting helps to reduce RAM consumption.

Minimal value and default value: 0, no limitation is set.

sort_overflow_mode

enum OverflowMode

Determines the behavior on exceeding limits while sorting.

• throw-abort query execution, return an error.
• break-stop query execution, return partial result.

• OVERFLOW_MODE_UNSPECIFIED
• OVERFLOW_MODE_THROW
• OVERFLOW_MODE_BREAK

max_result_rows

google.protobuf.Int64Value

Limits the number of rows in the result.
This limitation is also checked for subqueries and parts of distributed queries that run on remote servers.

Minimal value and default value: 0, no limitation is set.

max_result_bytes

google.protobuf.Int64Value

Limits the number of bytes in the result.
This limitation is also checked for subqueries and parts of distributed queries that run on remote servers.

Minimal value and default value: 0, no limitation is set.

result_overflow_mode

enum OverflowMode

Determines the behavior on exceeding limits while forming result.

• throw-abort query execution, return an error.
• break-stop query execution, return partial result.

• OVERFLOW_MODE_UNSPECIFIED
• OVERFLOW_MODE_THROW
• OVERFLOW_MODE_BREAK

max_rows_in_distinct

google.protobuf.Int64Value

Limits the maximum number of different rows when using DISTINCT.

Minimal value and default value: 0, no limitation is set.

max_bytes_in_distinct

google.protobuf.Int64Value

Limits the maximum size of a hash table in bytes (uncompressed data) when using DISTINCT.

distinct_overflow_mode

enum OverflowMode

Determines the behavior on exceeding limits while doing DISCTINCT.

• throw-abort query execution, return an error.
• break-stop query execution, return partial result.

• OVERFLOW_MODE_UNSPECIFIED
• OVERFLOW_MODE_THROW
• OVERFLOW_MODE_BREAK

max_rows_to_transfer

google.protobuf.Int64Value

Limits the maximum number of rows that can be passed to a remote server or saved in a temporary table when using GLOBAL IN.

Minimal value and default value: 0, no limitation is set.

max_bytes_to_transfer

google.protobuf.Int64Value

Limits the maximum number of bytes (uncompressed data) that can be passed to a remote server or saved in a temporary
table when using GLOBAL IN.

Minimal value and default value: 0, no limitation is set.

transfer_overflow_mode

enum OverflowMode

Determines the behavior on exceeding limits while doing transfers.

• throw-abort query execution, return an error.
• break-stop query execution, return partial result.

• OVERFLOW_MODE_UNSPECIFIED
• OVERFLOW_MODE_THROW
• OVERFLOW_MODE_BREAK

max_execution_time

google.protobuf.Int64Value

Limits the maximum query execution time in milliseconds.
At this moment, this limitation is not checked when passing one of the sorting stages, as well as merging and finalizing aggregation funictions.

Minimal value and default value: 0, no limitation is set.

timeout_overflow_mode

enum OverflowMode

Determines the behavior on exceeding limits of execution time.

• throw-abort query execution, return an error.
• break-stop query execution, return partial result.

• OVERFLOW_MODE_UNSPECIFIED
• OVERFLOW_MODE_THROW
• OVERFLOW_MODE_BREAK

max_rows_in_set

google.protobuf.Int64Value

Limit on the number of rows in the set resulting from the execution of the IN section.

max_bytes_in_set

google.protobuf.Int64Value

Limit on the number of bytes in the set resulting from the execution of the IN section.

set_overflow_mode

enum OverflowMode

Determine the behavior on exceeding max_rows_in_set or max_bytes_in_set limit.
Possible values: OVERFLOW_MODE_THROW, OVERFLOW_MODE_BREAK.

• OVERFLOW_MODE_UNSPECIFIED
• OVERFLOW_MODE_THROW
• OVERFLOW_MODE_BREAK

max_rows_in_join

google.protobuf.Int64Value

Limit on maximum size of the hash table for JOIN, in rows.

max_bytes_in_join

google.protobuf.Int64Value

Limit on maximum size of the hash table for JOIN, in bytes.

join_overflow_mode

enum OverflowMode

Determine the behavior on exceeding max_rows_in_join or max_bytes_in_join limit.
Possible values: OVERFLOW_MODE_THROW, OVERFLOW_MODE_BREAK.

• OVERFLOW_MODE_UNSPECIFIED
• OVERFLOW_MODE_THROW
• OVERFLOW_MODE_BREAK

join_algorithm[]

enum JoinAlgorithm

See in-depth description in ClickHouse documentation.

• JOIN_ALGORITHM_UNSPECIFIED
• JOIN_ALGORITHM_HASH
• JOIN_ALGORITHM_PARALLEL_HASH
• JOIN_ALGORITHM_PARTIAL_MERGE
• JOIN_ALGORITHM_DIRECT
• JOIN_ALGORITHM_AUTO
• JOIN_ALGORITHM_FULL_SORTING_MERGE
• JOIN_ALGORITHM_PREFER_PARTIAL_MERGE

any_join_distinct_right_table_keys

google.protobuf.BoolValue

See in-depth description in ClickHouse documentation.

max_columns_to_read

google.protobuf.Int64Value

Limits the maximum number of columns that can be read from a table in a single query.
If the query requires to read more columns to complete, then it will be aborted.

Minimal value and default value: 0, no limitation is set.

max_temporary_columns

google.protobuf.Int64Value

Limits the maximum number of temporary columns that must be kept in RAM at the same time when running a query, including constant columns.

Minimal value and default value: 0, no limitation is set.

max_temporary_non_const_columns

google.protobuf.Int64Value

Limits the maximum number of temporary columns that must be kept in RAM at the same time when running a query, excluding constant columns.

Minimal value and default value: 0, no limitation is set.

max_query_size

google.protobuf.Int64Value

Limits the size of the part of a query that can be transferred to RAM for parsing with the SQL parser, in bytes.

Value must be greater than 0 (default: 262144).

See in-depth description in ClickHouse documentation.

max_ast_depth

google.protobuf.Int64Value

Limits the maximum depth of query syntax tree.

Executing a big and complex query may result in building a syntax tree of enormous depth.
By using this setting, you can prohibit execution of over-sized or non-optimized queries for huge tables.

For example, the **SELECT *** query may result in more complex and deeper syntax tree, compared to the SELECT ... WHERE ... query, containing constraints and conditions, in the most cases.
A user can be forced to construct more optimized queries, if this setting is used.

Value must be greater than 0 (default: 1000).
If a too small value is set, it may render ClickHouse unable to execute even simple queries.

See in-depth description in ClickHouse documentation.

max_ast_elements

google.protobuf.Int64Value

Limits the maximum size of query syntax tree in number of nodes.

Executing a big and complex query may result in building a syntax tree of enormous size.
By using this setting, you can prohibit execution of over-sized or non-optimized queries for huge tables.

Value must be greater than 0 (default: 50000).
If a too small value is set, it may render ClickHouse unable to execute even simple queries.

See in-depth description in ClickHouse documentation.

max_expanded_ast_elements

google.protobuf.Int64Value

Limits the maximum size of query syntax tree in number of nodes after expansion of aliases and the asterisk values.

Executing a big and complex query may result in building a syntax tree of enormous size.
By using this setting, you can prohibit execution of over-sized or non-optimized queries for huge tables.

Value must be greater than 0 (default: 500000).
If a too small value is set, it may render ClickHouse unable to execute even simple queries.

min_execution_speed

google.protobuf.Int64Value

Minimal execution speed in rows per second.

min_execution_speed_bytes

google.protobuf.Int64Value

Minimal execution speed in bytes per second.

count_distinct_implementation

enum CountDistinctImplementation

Aggregate function to use for implementation of count(DISTINCT ...).

• COUNT_DISTINCT_IMPLEMENTATION_UNSPECIFIED
• COUNT_DISTINCT_IMPLEMENTATION_UNIQ
• COUNT_DISTINCT_IMPLEMENTATION_UNIQ_COMBINED
• COUNT_DISTINCT_IMPLEMENTATION_UNIQ_COMBINED_64
• COUNT_DISTINCT_IMPLEMENTATION_UNIQ_HLL_12
• COUNT_DISTINCT_IMPLEMENTATION_UNIQ_EXACT

input_format_values_interpret_expressions

google.protobuf.BoolValue

Enables or disables SQL parser if the fast stream parser cannot parse the data.

Enable this setting, if the data that you want to insert into a table contains SQL expressions.

For example, the stream parser is unable to parse a value that contains now() expression; therefore an INSERT query for this value will fail and no data will be inserted into a table.
With enabled SQL parser, this expression is parsed correctly: the now() expression will be parsed as SQL function, interpreted, and the current date and time will be inserted into the table as a result.

This setting has effect only if you use Values format when inserting data.

Default value: true (SQL parser is enabled).

See in-depth description in ClickHouse documentation.

input_format_defaults_for_omitted_fields

google.protobuf.BoolValue

Enables or disables replacing omitted input values with default values of the respective columns when performing INSERT queries.

Default value: true (replacing is enabled).

input_format_null_as_default

google.protobuf.BoolValue

See in-depth description in ClickHouse documentation.

date_time_input_format

enum DateTimeInputFormat

See in-depth description in ClickHouse documentation.

• DATE_TIME_INPUT_FORMAT_UNSPECIFIED
• DATE_TIME_INPUT_FORMAT_BEST_EFFORT
• DATE_TIME_INPUT_FORMAT_BASIC
• DATE_TIME_INPUT_FORMAT_BEST_EFFORT_US

input_format_with_names_use_header

google.protobuf.BoolValue

See in-depth description in ClickHouse documentation.

output_format_json_quote_64bit_integers

google.protobuf.BoolValue

Enables quoting of 64-bit integers in JSON output format.

If this setting is enabled, then 64-bit integers (UInt64 and Int64) will be quoted when written to JSON output in order to maintain compatibility with the most of the JavaScript engines.
Otherwise, such integers will not be quoted.

Default value: false (quoting 64-bit integers is disabled).

output_format_json_quote_denormals

google.protobuf.BoolValue

Enables special floating-point values (+nan, -nan, +inf and -inf) in JSON output format.

Default value: false (special values do not present in output).

date_time_output_format

enum DateTimeOutputFormat

See in-depth description in ClickHouse documentation.

• DATE_TIME_OUTPUT_FORMAT_UNSPECIFIED
• DATE_TIME_OUTPUT_FORMAT_SIMPLE
• DATE_TIME_OUTPUT_FORMAT_ISO
• DATE_TIME_OUTPUT_FORMAT_UNIX_TIMESTAMP

low_cardinality_allow_in_native_format

google.protobuf.BoolValue

Determines whether to use LowCardinality type in Native format.

• true (default)-yes, use.
• false-convert LowCardinality columns to regular columns when doing SELECT, and convert regular columns to LowCardinality when doing INSERT.

LowCardinality columns (aka sparse columns) store data in more effective way, compared to regular columns, by using hash tables.
If data to insert suits this storage format, ClickHouse will place them into LowCardinality column.

If you use a third-party ClickHouse client that can't work with LowCardinality columns, then this client will not be able to correctly interpret the result of the query that asks for data stored in LowCardinality column.
Disable this setting to convert LowCardinality column to regular column when creating the result, so such clients will be able to process the result.

Official ClickHouse client works with LowCardinality columns out-of-the-box.

Default value: true (LowCardinality columns are used in Native format).

allow_suspicious_low_cardinality_types

google.protobuf.BoolValue

Allows specifying LowCardinality modifier for types of small fixed size (8 or less) in CREATE TABLE statements. Enabling this may increase merge times and memory consumption.

More info see in ClickHouse documentation.

empty_result_for_aggregation_by_empty_set

google.protobuf.BoolValue

Enables returning of empty result when aggregating without keys (with GROUP BY operation absent) on empty set (e.g., SELECT count(*) FROM table WHERE 0).

• true-ClickHouse will return an empty result for such queries.
• false (default)-ClickHouse will return a single-line result consisting of NULL values for aggregation functions, in accordance with SQL standard.

http_connection_timeout

google.protobuf.Int64Value

HTTP connection timeout, in milliseconds.

Value must be greater than 0 (default: 1000, 1 second).

http_receive_timeout

google.protobuf.Int64Value

HTTP receive timeout, in milliseconds.

Value must be greater than 0 (default: 1800000, 1800 seconds, 30 minutes).

http_send_timeout

google.protobuf.Int64Value

HTTP send timeout, in milliseconds.

Value must be greater than 0 (default: 1800000, 1800 seconds, 30 minutes).

enable_http_compression

google.protobuf.BoolValue

Enables or disables data compression in HTTP responses.

By default, ClickHouse stores data compressed. When executing a query, its result is uncompressed.
Use this setting to command ClickHouse to compress the result when sending it via HTTP.

Enable this setting and add the Accept-Encoding: HTTP header in a HTTP request to force compression of HTTP response from ClickHouse.

ClickHouse support the following compression methods: gzip, br and deflate.

Default value: false (compression is disabled).

See in-depth description in ClickHouse documentation.

send_progress_in_http_headers

google.protobuf.BoolValue

Enables progress notifications using X-ClickHouse-Progress HTTP header.

Default value: false (notifications disabled).

http_headers_progress_interval

google.protobuf.Int64Value

Minimum interval between progress notifications with X-ClickHouse-Progress HTTP header, in milliseconds.

Value must be greater than 0 (default: 100).

add_http_cors_header

google.protobuf.BoolValue

Adds CORS header in HTTP responses.

Default value: false (header is not added).

cancel_http_readonly_queries_on_client_close

google.protobuf.BoolValue

Cancels HTTP read-only queries (e.g. SELECT) when a client closes the connection without waiting for the response.

Default value: false.

More info see in ClickHouse documentation.

max_http_get_redirects

google.protobuf.Int64Value

Limits the maximum number of HTTP GET redirect hops for URL-engine tables.

If the parameter is set to 0 (default), no hops is allowed.

More info see in ClickHouse documentation.

joined_subquery_requires_alias

google.protobuf.BoolValue

join_use_nulls

google.protobuf.BoolValue

transform_null_in

google.protobuf.BoolValue

quota_mode

enum QuotaMode

Quota accounting mode. Possible values: QUOTA_MODE_DEFAULT, QUOTA_MODE_KEYED and QUOTA_MODE_KEYED_BY_IP.

• QUOTA_MODE_UNSPECIFIED
• QUOTA_MODE_DEFAULT
• QUOTA_MODE_KEYED
• QUOTA_MODE_KEYED_BY_IP

flatten_nested

google.protobuf.BoolValue

Sets the data format of a nested columns.

More info see in ClickHouse documentation.

format_regexp

string

Regular expression (for Regexp format)

format_regexp_escaping_rule

enum FormatRegexpEscapingRule

See in-depth description in ClickHouse documentation.

• FORMAT_REGEXP_ESCAPING_RULE_UNSPECIFIED
• FORMAT_REGEXP_ESCAPING_RULE_ESCAPED
• FORMAT_REGEXP_ESCAPING_RULE_QUOTED
• FORMAT_REGEXP_ESCAPING_RULE_CSV
• FORMAT_REGEXP_ESCAPING_RULE_JSON
• FORMAT_REGEXP_ESCAPING_RULE_XML
• FORMAT_REGEXP_ESCAPING_RULE_RAW

format_regexp_skip_unmatched

google.protobuf.BoolValue

See in-depth description in ClickHouse documentation.

async_insert

google.protobuf.BoolValue

Enables asynchronous inserts.

Disabled by default.

More info see in ClickHouse documentation.

async_insert_threads

google.protobuf.Int64Value

The maximum number of threads for background data parsing and insertion.

If the parameter is set to 0, asynchronous insertions are disabled. Default value: 16.

More info see in ClickHouse documentation.

wait_for_async_insert

google.protobuf.BoolValue

Enables waiting for processing of asynchronous insertion. If enabled, server returns OK only after the data is inserted.

More info see in ClickHouse documentation.

wait_for_async_insert_timeout

google.protobuf.Int64Value

The timeout (in seconds) for waiting for processing of asynchronous insertion.

Default value: 120.

More info see in ClickHouse documentation.

async_insert_max_data_size

google.protobuf.Int64Value

The maximum size of the unparsed data in bytes collected per query before being inserted.

If the parameter is set to 0, asynchronous insertions are disabled. Default value: 100000.

More info see in ClickHouse documentation.

async_insert_busy_timeout

google.protobuf.Int64Value

The maximum timeout in milliseconds since the first INSERT query before inserting collected data.

If the parameter is set to 0, the timeout is disabled. Default value: 200.

More info see in ClickHouse documentation.

async_insert_stale_timeout

google.protobuf.Int64Value

The maximum timeout in milliseconds since the last INSERT query before dumping collected data. If enabled, the settings prolongs the async_insert_busy_timeout with every INSERT query as long as async_insert_max_data_size is not exceeded.

More info see in ClickHouse documentation.

memory_profiler_step

google.protobuf.Int64Value

Memory profiler step (in bytes).

If the next query step requires more memory than this parameter specifies, the memory profiler collects the allocating stack trace. Values lower than a few megabytes slow down query processing.

Default value: 4194304 (4 MB). Zero means disabled memory profiler.

memory_profiler_sample_probability

google.protobuf.DoubleValue

Collect random allocations and deallocations and write them into system.trace_log with 'MemorySample' trace_type. The probability is for every alloc/free regardless to the size of the allocation.

Possible values: from 0 to 1. Default: 0.

max_final_threads

google.protobuf.Int64Value

Sets the maximum number of parallel threads for the SELECT query data read phase with the FINAL modifier.
See in-depth description in ClickHouse documentation.

input_format_parallel_parsing

google.protobuf.BoolValue

Enables or disables order-preserving parallel parsing of data formats. Supported only for TSV, TKSV, CSV and JSONEachRow formats.
See in-depth description in ClickHouse documentation

input_format_import_nested_json

google.protobuf.BoolValue

Enables or disables the insertion of JSON data with nested objects.
See in-depth description in ClickHouse documentation

local_filesystem_read_method

enum LocalFilesystemReadMethod

Method of reading data from local filesystem, one of: read, pread, mmap, io_uring, pread_threadpool. The 'io_uring' method is experimental and does not work for Log, TinyLog, StripeLog, File, Set and Join, and other tables with append-able files in presence of concurrent reads and writes.

• LOCAL_FILESYSTEM_READ_METHOD_UNSPECIFIED
• LOCAL_FILESYSTEM_READ_METHOD_READ
• LOCAL_FILESYSTEM_READ_METHOD_PREAD_THREADPOOL
• LOCAL_FILESYSTEM_READ_METHOD_PREAD
• LOCAL_FILESYSTEM_READ_METHOD_NMAP

max_read_buffer_size

google.protobuf.Int64Value

The maximum size of the buffer to read from the filesystem.
See in-depth description in ClickHouse documentation

insert_keeper_max_retries

google.protobuf.Int64Value

The setting sets the maximum number of retries for ClickHouse Keeper (or ZooKeeper) requests during insert into replicated MergeTree. Only Keeper requests which failed due to network error, Keeper session timeout, or request timeout are considered for retries.
Default: 20 from 23.2, 0(disabled) before
Min_version: 22.11
See in-depth description in ClickHouse documentation

max_temporary_data_on_disk_size_for_user

google.protobuf.Int64Value

The maximum amount of data consumed by temporary files on disk in bytes for all concurrently running user queries. Zero means unlimited.
Default: 0 - unlimited
Min_version: 22.10
See in-depth description in ClickHouse documentation

max_temporary_data_on_disk_size_for_query

google.protobuf.Int64Value

The maximum amount of data consumed by temporary files on disk in bytes for all concurrently running queries. Zero means unlimited.
Default: 0 - unlimited
Min_version: 22.10
See in-depth description in ClickHouse documentation

max_parser_depth

google.protobuf.Int64Value

Limits maximum recursion depth in the recursive descent parser. Allows controlling the stack size.
Default: 1000
Special: 0 - unlimited
See in-depth description in ClickHouse documentation

remote_filesystem_read_method

enum RemoteFilesystemReadMethod

Method of reading data from remote filesystem, one of: read, threadpool.
Default: read
Min_version: 21.11
See in-depth description in ClickHouse GitHub

• REMOTE_FILESYSTEM_READ_METHOD_UNSPECIFIED
• REMOTE_FILESYSTEM_READ_METHOD_READ
• REMOTE_FILESYSTEM_READ_METHOD_THREADPOOL

memory_overcommit_ratio_denominator

google.protobuf.Int64Value

It represents soft memory limit in case when hard limit is reached on user level. This value is used to compute overcommit ratio for the query. Zero means skip the query.
Default: 1GiB
Min_version: 22.5
See in-depth description in ClickHouse documentation

memory_overcommit_ratio_denominator_for_user

google.protobuf.Int64Value

It represents soft memory limit in case when hard limit is reached on global level. This value is used to compute overcommit ratio for the query. Zero means skip the query.
Default: 1GiB
Min_version: 22.5
See in-depth description in ClickHouse documentation

memory_usage_overcommit_max_wait_microseconds

google.protobuf.Int64Value

Maximum time thread will wait for memory to be freed in the case of memory overcommit on a user level. If the timeout is reached and memory is not freed, an exception is thrown.
Default: 5000000
Min_version: 22.5
See in-depth description in ClickHouse documentation

log_query_threads

google.protobuf.BoolValue

Setting up query threads logging. Query threads log into the system.query_thread_log table. This setting has effect only when log_queries is true. Queries threads run by ClickHouse with this setup are logged according to the rules in the query_thread_log server configuration parameter.
Default: true
See in-depth description in ClickHouse documentation

max_insert_threads

google.protobuf.Int64Value

The maximum number of threads to execute the INSERT SELECT query.
Default: 0
See in-depth description in ClickHouse documentation

use_hedged_requests

google.protobuf.BoolValue

Enables hedged requests logic for remote queries. It allows to establish many connections with different replicas for query. New connection is enabled in case existent connection(s) with replica(s) were not established within hedged_connection_timeout or no data was received within receive_data_timeout. Query uses the first connection which send non empty progress packet (or data packet, if allow_changing_replica_until_first_data_packet); other connections are cancelled. Queries with max_parallel_replicas > 1 are supported.
Default: true
See in-depth description in ClickHouse documentation

idle_connection_timeout

google.protobuf.Int64Value

Timeout to close idle TCP connections after specified number of milliseconds.
Default: 360000 (3600 seconds)
See in-depth description in ClickHouse documentation

hedged_connection_timeout_ms

google.protobuf.Int64Value

Connection timeout for establishing connection with replica for Hedged requests.
Default: 50
See in-depth description in ClickHouse GitHub

load_balancing

enum LoadBalancing

Specifies the algorithm of replicas selection that is used for distributed query processing, one of: random, nearest_hostname, in_order, first_or_random, round_robin.
Default: random
See in-depth description in ClickHouse documentation

• LOAD_BALANCING_UNSPECIFIED
• LOAD_BALANCING_RANDOM
• LOAD_BALANCING_NEAREST_HOSTNAME
• LOAD_BALANCING_IN_ORDER
• LOAD_BALANCING_FIRST_OR_RANDOM
• LOAD_BALANCING_ROUND_ROBIN

prefer_localhost_replica

google.protobuf.BoolValue

Enables/disables preferable using the localhost replica when processing distributed queries.
Default: true
See in-depth description in ClickHouse documentation

compile

google.protobuf.BoolValue

The setting is deprecated and has no effect.

min_count_to_compile

google.protobuf.Int64Value

The setting is deprecated and has no effect.

Field

Description

interval_duration

google.protobuf.Int64Value

Duration of interval for quota in milliseconds.
Minimal value is 1 second.

queries

google.protobuf.Int64Value

The total number of queries.
0 - unlimited.

errors

google.protobuf.Int64Value

The number of queries that threw exception.
0 - unlimited.

result_rows

google.protobuf.Int64Value

The total number of rows given as the result..
0 - unlimited.

read_rows

google.protobuf.Int64Value

The total number of source rows read from tables for running the query, on all remote servers.
0 - unlimited.

execution_time

google.protobuf.Int64Value

The total query execution time, in milliseconds (wall time).
0 - unlimited.