usage: clickhouse-local [initial table definition] [--query ] clickhouse-local allows to execute SQL queries on your data files via single command line call. To do so, initially you need to define your data source and its format. After you can execute your SQL queries in usual manner. There are two ways to define initial table keeping your data. Either just in first query like this: CREATE TABLE () ENGINE = File(, ); Either through corresponding command line parameters --table --structure --input-format and --file. Main options: --help produce help message -V [ --version ] print version information and exit --version-clean print version in machine-readable format and exit -C [ --config-file ] arg config-file path --queries-file arg file path with queries to execute; multiple files can be specified (--queries-file file1 file2...) -d [ --database ] arg database --history_file arg path to history file -q [ --query ] arg query --stage arg (=complete) Request query processing up to specified stage: complete,fetch_columns ,with_mergeable_state,with_mergeable_st ate_after_aggregation,with_mergeable_st ate_after_aggregation_and_limit --query_kind arg (=initial_query) One of initial_query/secondary_query/no _query --query_id arg query_id --progress print progress of queries execution -A [ --disable_suggestion ] Disable loading suggestion data. Note that suggestion data is loaded asynchronously through a second connection to ClickHouse server. Also it is reasonable to disable suggestion if you want to paste a query with TAB characters. Shorthand option -A is for those who get used to mysql client. -t [ --time ] print query execution time to stderr in non-interactive mode (for benchmarks) --echo in batch mode, print query before execution --verbose print query and other debugging info --log-level arg log level --server_logs_file arg put server logs into specified file -m [ --multiline ] multiline -n [ --multiquery ] multiquery --suggestion_limit arg (=10000) Suggestion limit for how many databases, tables and columns to fetch. -f [ --format ] arg default output format -E [ --vertical ] vertical output format, same as --format=Vertical or FORMAT Vertical or \G at end of command --highlight arg (=1) enable or disable basic syntax highlight in interactive command line --ignore-error do not stop processing in multiquery mode --stacktrace print stack traces of exceptions --hardware-utilization print hardware utilization information in progress bar --print-profile-events Printing ProfileEvents packets --profile-events-delay-ms arg (=0) Delay between printing `ProfileEvents` packets (-1 - print only totals, 0 - print every single packet) --interactive Process queries-file or --query query and start interactive mode --pager arg Pipe all output into this command (less or similar) --max_memory_usage_in_client arg Set memory limit in client/local server -N [ --table ] arg name of the initial table -S [ --structure ] arg structure of the initial table (list of column and type names) -f [ --file ] arg path to file with data of the initial table (stdin if not specified) --input-format arg input format of the initial table data --output-format arg default output format --logger.console [=arg(=1)] Log to console --logger.log arg Log file name --logger.level arg Log level --no-system-tables do not attach system tables (better startup time) --path arg Storage path --top_level_domains_path arg Path to lists with custom TLDs --min_compress_block_size arg The actual size of the block to compress, if the uncompressed data less than max_compress_block_size is no less than this value and no less than the volume of data for one mark. --max_compress_block_size arg The maximum size of blocks of uncompressed data before compressing for writing to a table. --max_block_size arg Maximum block size for reading --max_insert_block_size arg The maximum block size for insertion, if we control the creation of blocks for insertion. --min_insert_block_size_rows arg Squash blocks passed to INSERT query to specified size in rows, if blocks are not big enough. --min_insert_block_size_bytes arg Squash blocks passed to INSERT query to specified size in bytes, if blocks are not big enough. --min_insert_block_size_rows_for_materialized_views arg Like min_insert_block_size_rows, but applied only during pushing to MATERIALIZED VIEW (default: min_insert_block_size_rows) --min_insert_block_size_bytes_for_materialized_views arg Like min_insert_block_size_bytes, but applied only during pushing to MATERIALIZED VIEW (default: min_insert_block_size_bytes) --max_joined_block_size_rows arg Maximum block size for JOIN result (if join algorithm supports it). 0 means unlimited. --max_insert_threads arg The maximum number of threads to execute the INSERT SELECT query. Values 0 or 1 means that INSERT SELECT is not run in parallel. Higher values will lead to higher memory usage. Parallel INSERT SELECT has effect only if the SELECT part is run on parallel, see 'max_threads' setting. --max_insert_delayed_streams_for_parallel_write arg The maximum number of streams (columns) to delay final part flush. Default - auto (1000 in case of underlying storage supports parallel write, for example S3 and disabled otherwise) --max_final_threads arg The maximum number of threads to read from table with FINAL. --max_threads arg The maximum number of threads to execute the request. By default, it is determined automatically. --max_download_threads arg The maximum number of threads to download data (e.g. for URL engine). --max_download_buffer_size arg The maximal size of buffer for parallel downloading (e.g. for URL engine) per each thread. --max_read_buffer_size arg The maximum size of the buffer to read from the filesystem. --max_distributed_connections arg The maximum number of connections for distributed processing of one query (should be greater than max_threads). --max_query_size arg Which part of the query can be read into RAM for parsing (the remaining data for INSERT, if any, is read later) --interactive_delay arg The interval in microseconds to check if the request is cancelled, and to send progress info. --connect_timeout arg Connection timeout if there are no replicas. --connect_timeout_with_failover_ms arg Connection timeout for selecting first healthy replica. --connect_timeout_with_failover_secure_ms arg Connection timeout for selecting first healthy replica (for secure connections). --receive_timeout arg --send_timeout arg --drain_timeout arg Timeout for draining remote connections, -1 means synchronous drain without ignoring errors --tcp_keep_alive_timeout arg The time in seconds the connection needs to remain idle before TCP starts sending keepalive probes --hedged_connection_timeout_ms arg Connection timeout for establishing connection with replica for Hedged requests --receive_data_timeout_ms arg Connection timeout for receiving first packet of data or packet with positive progress from replica --use_hedged_requests arg Use hedged requests for distributed queries --allow_changing_replica_until_first_data_packet arg Allow HedgedConnections to change replica until receiving first data packet --queue_max_wait_ms arg The wait time in the request queue, if the number of concurrent requests exceeds the maximum. --connection_pool_max_wait_ms arg The wait time when the connection pool is full. --replace_running_query_max_wait_ms arg The wait time for running query with the same query_id to finish when setting 'replace_running_query' is active. --kafka_max_wait_ms arg The wait time for reading from Kafka before retry. --rabbitmq_max_wait_ms arg The wait time for reading from RabbitMQ before retry. --poll_interval arg Block at the query wait loop on the server for the specified number of seconds. --idle_connection_timeout arg Close idle TCP connections after specified number of seconds. --distributed_connections_pool_size arg Maximum number of connections with one remote server in the pool. --connections_with_failover_max_tries arg The maximum number of attempts to connect to replicas. --s3_min_upload_part_size arg The minimum size of part to upload during multipart upload to S3. --s3_upload_part_size_multiply_factor arg Multiply s3_min_upload_part_size by this factor each time s3_multiply_parts_count_threshold parts were uploaded from a single write to S3. --s3_upload_part_size_multiply_parts_count_threshold arg Each time this number of parts was uploaded to S3 s3_min_upload_part_size multiplied by s3_upload_part_size_multi ply_factor. --s3_max_single_part_upload_size arg The maximum size of object to upload using singlepart upload to S3. --s3_max_single_read_retries arg The maximum number of retries during single S3 read. --s3_max_redirects arg Max number of S3 redirects hops allowed. --s3_max_connections arg The maximum number of connections per server. --s3_truncate_on_insert arg Enables or disables truncate before insert in s3 engine tables. --s3_create_new_file_on_insert arg Enables or disables creating a new file on each insert in s3 engine tables --s3_check_objects_after_upload arg Check each uploaded object to s3 with head request to be sure that upload was successful --s3_allow_parallel_part_upload arg Use multiple threads for s3 multipart upload. It may lead to slightly higher memory usage --enable_s3_requests_logging arg Enable very explicit logging of S3 requests. Makes sense for debug only. --hdfs_replication arg The actual number of replications can be specified when the hdfs file is created. --hdfs_truncate_on_insert arg Enables or disables truncate before insert in s3 engine tables --hdfs_create_new_file_on_insert arg Enables or disables creating a new file on each insert in hdfs engine tables --hsts_max_age arg Expired time for hsts. 0 means disable HSTS. --extremes arg Calculate minimums and maximums of the result columns. They can be output in JSON-formats. --use_uncompressed_cache arg Whether to use the cache of uncompressed blocks. --replace_running_query arg Whether the running request should be canceled with the same id as the new one. --max_replicated_fetches_network_bandwidth_for_server arg The maximum speed of data exchange over the network in bytes per second for replicated fetches. Zero means unlimited. Only has meaning at server startup. --max_replicated_sends_network_bandwidth_for_server arg The maximum speed of data exchange over the network in bytes per second for replicated sends. Zero means unlimited. Only has meaning at server startup. --max_remote_read_network_bandwidth_for_server arg The maximum speed of data exchange over the network in bytes per second for read. Zero means unlimited. Only has meaning at server startup. --max_remote_write_network_bandwidth_for_server arg The maximum speed of data exchange over the network in bytes per second for write. Zero means unlimited. Only has meaning at server startup. --stream_like_engine_allow_direct_select arg Allow direct SELECT query for Kafka, RabbitMQ, FileLog, Redis Streams and NATS engines. In case there are attached materialized views, SELECT query is not allowed even if this setting is enabled. --stream_like_engine_insert_queue arg When stream like engine reads from multiple queues, user will need to select one queue to insert into when writing. Used by Redis Streams and NATS. --distributed_directory_monitor_sleep_time_ms arg Sleep time for StorageDistributed DirectoryMonitors, in case of any errors delay grows exponentially. --distributed_directory_monitor_max_sleep_time_ms arg Maximum sleep time for StorageDistributed DirectoryMonitors, it limits exponential growth too. --distributed_directory_monitor_batch_inserts arg Should StorageDistributed DirectoryMonitors try to batch individual inserts into bigger ones. --distributed_directory_monitor_split_batch_on_failure arg Should StorageDistributed DirectoryMonitors try to split batch into smaller in case of failures. --optimize_move_to_prewhere arg Allows disabling WHERE to PREWHERE optimization in SELECT queries from MergeTree. --optimize_move_to_prewhere_if_final arg If query has `FINAL`, the optimization `move_to_prewhere` is not always correct and it is enabled only if both settings `optimize_move_to_prewhere` and `optimize_move_to_prewhere_if_final ` are turned on --replication_alter_partitions_sync arg Wait for actions to manipulate the partitions. 0 - do not wait, 1 - wait for execution only of itself, 2 - wait for everyone. --replication_wait_for_inactive_replica_timeout arg Wait for inactive replica to execute ALTER/OPTIMIZE. Time in seconds, 0 - do not wait, negative - wait for unlimited time. --load_balancing arg Which replicas (among healthy replicas) to preferably send a query to (on the first attempt) for distributed processing. --load_balancing_first_offset arg Which replica to preferably send a query when FIRST_OR_RANDOM load balancing strategy is used. --totals_mode arg How to calculate TOTALS when HAVING is present, as well as when max_rows_to_group_by and group_by_overflow_mode = ‘any’ are present. --totals_auto_threshold arg The threshold for totals_mode = 'auto'. --allow_suspicious_low_cardinality_types arg In CREATE TABLE statement allows specifying LowCardinality modifier for types of small fixed size (8 or less). Enabling this may increase merge times and memory consumption. --compile_expressions arg Compile some scalar functions and operators to native code. --min_count_to_compile_expression arg The number of identical expressions before they are JIT-compiled --compile_aggregate_expressions arg Compile aggregate functions to native code. This feature has a bug and should not be used. --min_count_to_compile_aggregate_expression arg The number of identical aggregate expressions before they are JIT-compiled --compile_sort_description arg Compile sort description to native code. --min_count_to_compile_sort_description arg The number of identical sort descriptions before they are JIT-compiled --group_by_two_level_threshold arg From what number of keys, a two-level aggregation starts. 0 - the threshold is not set. --group_by_two_level_threshold_bytes arg From what size of the aggregation state in bytes, a two-level aggregation begins to be used. 0 - the threshold is not set. Two-level aggregation is used when at least one of the thresholds is triggered. --distributed_aggregation_memory_efficient arg Is the memory-saving mode of distributed aggregation enabled. --aggregation_memory_efficient_merge_threads arg Number of threads to use for merge intermediate aggregation results in memory efficient mode. When bigger, then more memory is consumed. 0 means - same as 'max_threads'. --enable_positional_arguments arg Enable positional arguments in ORDER BY, GROUP BY and LIMIT BY --group_by_use_nulls arg Treat columns mentioned in ROLLUP, CUBE or GROUPING SETS as Nullable --max_parallel_replicas arg The maximum number of replicas of each shard used when the query is executed. For consistency (to get different parts of the same partition), this option only works for the specified sampling key. The lag of the replicas is not controlled. --parallel_replicas_count arg --parallel_replica_offset arg --allow_experimental_parallel_reading_from_replicas arg If true, ClickHouse will send a SELECT query to all replicas of a table. It will work for any kind on MergeTree table. --skip_unavailable_shards arg If true, ClickHouse silently skips unavailable shards and nodes unresolvable through DNS. Shard is marked as unavailable when none of the replicas can be reached. --parallel_distributed_insert_select arg Process distributed INSERT SELECT query in the same cluster on local tables on every shard; if set to 1 - SELECT is executed on each shard; if set to 2 - SELECT and INSERT are executed on each shard --distributed_group_by_no_merge arg If 1, Do not merge aggregation states from different servers for distributed queries (shards will process query up to the Complete stage, initiator just proxies the data from the shards). If 2 the initiator will apply ORDER BY and LIMIT stages (it is not in case when shard process query up to the Complete stage) --distributed_push_down_limit arg If 1, LIMIT will be applied on each shard separatelly. Usually you don't need to use it, since this will be done automatically if it is possible, i.e. for simple query SELECT FROM LIMIT. --optimize_distributed_group_by_sharding_key arg Optimize GROUP BY sharding_key queries (by avoiding costly aggregation on the initiator server). --optimize_skip_unused_shards_limit arg Limit for number of sharding key values, turns off optimize_skip_unused_ shards if the limit is reached --optimize_skip_unused_shards arg Assumes that data is distributed by sharding_key. Optimization to skip unused shards if SELECT query filters by sharding_key. --optimize_skip_unused_shards_rewrite_in arg Rewrite IN in query for remote shards to exclude values that does not belong to the shard (requires optimize_skip_unused_shards) --allow_nondeterministic_optimize_skip_unused_shards arg Allow non-deterministic functions (includes dictGet) in sharding_key for optimize_skip_unused_shards --force_optimize_skip_unused_shards arg Throw an exception if unused shards cannot be skipped (1 - throw only if the table has the sharding key, 2 - always throw. --optimize_skip_unused_shards_nesting arg Same as optimize_skip_unused_shards, but accept nesting level until which it will work. --force_optimize_skip_unused_shards_nesting arg Same as force_optimize_skip_unused_shar ds, but accept nesting level until which it will work. --input_format_parallel_parsing arg Enable parallel parsing for some data formats. --min_chunk_bytes_for_parallel_parsing arg The minimum chunk size in bytes, which each thread will parse in parallel. --output_format_parallel_formatting arg Enable parallel formatting for some data formats. --merge_tree_min_rows_for_concurrent_read arg If at least as many lines are read from one file, the reading can be parallelized. --merge_tree_min_bytes_for_concurrent_read arg If at least as many bytes are read from one file, the reading can be parallelized. --merge_tree_min_rows_for_seek arg You can skip reading more than that number of rows at the price of one seek per file. --merge_tree_min_bytes_for_seek arg You can skip reading more than that number of bytes at the price of one seek per file. --merge_tree_coarse_index_granularity arg If the index segment can contain the required keys, divide it into as many parts and recursively check them. --merge_tree_max_rows_to_use_cache arg The maximum number of rows per request, to use the cache of uncompressed data. If the request is large, the cache is not used. (For large queries not to flush out the cache.) --merge_tree_max_bytes_to_use_cache arg The maximum number of bytes per request, to use the cache of uncompressed data. If the request is large, the cache is not used. (For large queries not to flush out the cache.) --do_not_merge_across_partitions_select_final arg Merge parts only in one partition in select final --mysql_max_rows_to_insert arg The maximum number of rows in MySQL batch insertion of the MySQL storage engine --optimize_min_equality_disjunction_chain_length arg The minimum length of the expression `expr = x1 OR ... expr = xN` for optimization --min_bytes_to_use_direct_io arg The minimum number of bytes for reading the data with O_DIRECT option during SELECT queries execution. 0 - disabled. --min_bytes_to_use_mmap_io arg The minimum number of bytes for reading the data with mmap option during SELECT queries execution. 0 - disabled. --checksum_on_read arg Validate checksums on reading. It is enabled by default and should be always enabled in production. Please do not expect any benefits in disabling this setting. It may only be used for experiments and benchmarks. The setting only applicable for tables of MergeTree family. Checksums are always validated for other table engines and when receiving data over network. --force_index_by_date arg Throw an exception if there is a partition key in a table, and it is not used. --force_primary_key arg Throw an exception if there is primary key in a table, and it is not used. --use_skip_indexes arg Use data skipping indexes during query execution. --use_skip_indexes_if_final arg If query has FINAL, then skipping data based on indexes may produce incorrect result, hence disabled by default. --force_data_skipping_indices arg Comma separated list of strings or literals with the name of the data skipping indices that should be used during query execution, otherwise an exception will be thrown. --max_streams_to_max_threads_ratio arg Allows you to use more sources than the number of threads - to more evenly distribute work across threads. It is assumed that this is a temporary solution, since it will be possible in the future to make the number of sources equal to the number of threads, but for each source to dynamically select available work for itself. --max_streams_multiplier_for_merge_tables arg Ask more streams when reading from Merge table. Streams will be spread across tables that Merge table will use. This allows more even distribution of work across threads and especially helpful when merged tables differ in size. --network_compression_method arg Allows you to select the method of data compression when writing. --network_zstd_compression_level arg Allows you to select the level of ZSTD compression. --zstd_window_log_max arg Allows you to select the max window log of ZSTD (it will not be used for MergeTree family) --priority arg Priority of the query. 1 - the highest, higher value - lower priority; 0 - do not use priorities. --os_thread_priority arg If non zero - set corresponding 'nice' value for query processing threads. Can be used to adjust query priority for OS scheduler. --log_queries arg Log requests and write the log to the system table. --log_formatted_queries arg Log formatted queries and write the log to the system table. --log_queries_min_type arg Minimal type in query_log to log, possible values (from low to high): QUERY_START, QUERY_FINISH, EXCEPTION_BEFORE_START, EXCEPTION_WHILE_PROCESSING. --log_queries_min_query_duration_ms arg Minimal time for the query to run, to get to the query_log/query_thread_log/q uery_views_log. --log_queries_cut_to_length arg If query length is greater than specified threshold (in bytes), then cut query when writing to query log. Also limit length of printed query in ordinary text log. --log_queries_probability arg Log queries with the specified probabality. --log_processors_profiles arg Log Processors profile events. --distributed_product_mode arg How are distributed subqueries performed inside IN or JOIN sections? --max_concurrent_queries_for_all_users arg The maximum number of concurrent requests for all users. --max_concurrent_queries_for_user arg The maximum number of concurrent requests per user. --insert_deduplicate arg For INSERT queries in the replicated table, specifies that deduplication of insertings blocks should be performed --insert_quorum arg For INSERT queries in the replicated table, wait writing for the specified number of replicas and linearize the addition of the data. 0 - disabled. --insert_quorum_timeout arg --insert_quorum_parallel arg For quorum INSERT queries - enable to make parallel inserts without linearizability --select_sequential_consistency arg For SELECT queries from the replicated table, throw an exception if the replica does not have a chunk written with the quorum; do not read the parts that have not yet been written with the quorum. --table_function_remote_max_addresses arg The maximum number of different shards and the maximum number of replicas of one shard in the `remote` function. --read_backoff_min_latency_ms arg Setting to reduce the number of threads in case of slow reads. Pay attention only to reads that took at least that much time. --read_backoff_max_throughput arg Settings to reduce the number of threads in case of slow reads. Count events when the read bandwidth is less than that many bytes per second. --read_backoff_min_interval_between_events_ms arg Settings to reduce the number of threads in case of slow reads. Do not pay attention to the event, if the previous one has passed less than a certain amount of time. --read_backoff_min_events arg Settings to reduce the number of threads in case of slow reads. The number of events after which the number of threads will be reduced. --read_backoff_min_concurrency arg Settings to try keeping the minimal number of threads in case of slow reads. --memory_tracker_fault_probability arg For testing of `exception safety` - throw an exception every time you allocate memory with the specified probability. --enable_http_compression arg Compress the result if the client over HTTP said that it understands data compressed by gzip or deflate. --http_zlib_compression_level arg Compression level - used if the client on HTTP said that it understands data compressed by gzip or deflate. --http_native_compression_disable_checksumming_on_decompress arg If you uncompress the POST data from the client compressed by the native format, do not check the checksum. --count_distinct_implementation arg What aggregate function to use for implementation of count(DISTINCT ...) --add_http_cors_header arg Write add http CORS header. --max_http_get_redirects arg Max number of http GET redirects hops allowed. Make sure additional security measures are in place to prevent a malicious server to redirect your requests to unexpected services. --use_client_time_zone arg Use client timezone for interpreting DateTime string values, instead of adopting server timezone. --send_progress_in_http_headers arg Send progress notifications using X-ClickHouse-Progress headers. Some clients do not support high amount of HTTP headers (Python requests in particular), so it is disabled by default. --http_headers_progress_interval_ms arg Do not send HTTP headers X-ClickHouse-Progress more frequently than at each specified interval. --fsync_metadata arg Do fsync after changing metadata for tables and databases (.sql files). Could be disabled in case of poor latency on server with high load of DDL queries and high load of disk subsystem. --join_use_nulls arg Use NULLs for non-joined rows of outer JOINs for types that can be inside Nullable. If false, use default value of corresponding columns data type. --join_default_strictness arg Set default strictness in JOIN query. Possible values: empty string, 'ANY', 'ALL'. If empty, query without strictness will throw exception. --any_join_distinct_right_table_keys arg Enable old ANY JOIN logic with many-to-one left-to-right table keys mapping for all ANY JOINs. It leads to confusing not equal results for 't1 ANY LEFT JOIN t2' and 't2 ANY RIGHT JOIN t1'. ANY RIGHT JOIN needs one-to-many keys mapping to be consistent with LEFT one. --preferred_block_size_bytes arg --max_replica_delay_for_distributed_queries arg If set, distributed queries of Replicated tables will choose servers with replication delay in seconds less than the specified value (not inclusive). Zero means do not take delay into account. --fallback_to_stale_replicas_for_distributed_queries arg Suppose max_replica_delay_for_distribut ed_queries is set and all replicas for the queried table are stale. If this setting is enabled, the query will be performed anyway, otherwise the error will be reported. --preferred_max_column_in_block_size_bytes arg Limit on max column size in block while reading. Helps to decrease cache misses count. Should be close to L2 cache size. --parts_to_delay_insert arg If the destination table contains at least that many active parts in a single partition, artificially slow down insert into table. --parts_to_throw_insert arg If more than this number active parts in a single partition of the destination table, throw 'Too many parts ...' exception. --insert_distributed_sync arg If setting is enabled, insert query into distributed waits until data will be sent to all nodes in cluster. --insert_distributed_timeout arg Timeout for insert query into distributed. Setting is used only with insert_distributed_sync enabled. Zero value means no timeout. --distributed_ddl_task_timeout arg Timeout for DDL query responses from all hosts in cluster. If a ddl request has not been performed on all hosts, a response will contain a timeout error and a request will be executed in an async mode. Negative value means infinite. Zero means async mode. --stream_flush_interval_ms arg Timeout for flushing data from streaming storages. --stream_poll_timeout_ms arg Timeout for polling data from/to streaming storages. --sleep_in_send_tables_status_ms arg Time to sleep in sending tables status response in TCPHandler --sleep_in_send_data_ms arg Time to sleep in sending data in TCPHandler --sleep_after_receiving_query_ms arg Time to sleep after receiving query in TCPHandler --unknown_packet_in_send_data arg Send unknown packet instead of data Nth data packet --sleep_in_receive_cancel_ms arg Time to sleep in receiving cancel in TCPHandler --insert_allow_materialized_columns arg If setting is enabled, Allow materialized columns in INSERT. --http_connection_timeout arg HTTP connection timeout. --http_send_timeout arg HTTP send timeout --http_receive_timeout arg HTTP receive timeout --http_max_uri_size arg Maximum URI length of HTTP request --http_max_fields arg Maximum number of fields in HTTP header --http_max_field_name_size arg Maximum length of field name in HTTP header --http_max_field_value_size arg Maximum length of field value in HTTP header --http_max_chunk_size arg Maximum value of a chunk size in HTTP chunked transfer encoding --http_skip_not_found_url_for_globs arg Skip url's for globs with HTTP_NOT_FOUND error --optimize_throw_if_noop arg If setting is enabled and OPTIMIZE query didn't actually assign a merge then an explanatory exception is thrown --use_index_for_in_with_subqueries arg Try using an index if there is a subquery or a table expression on the right side of the IN operator. --joined_subquery_requires_alias arg Force joined subqueries and table functions to have aliases for correct name qualification. --empty_result_for_aggregation_by_empty_set arg Return empty result when aggregating without keys on empty set. --empty_result_for_aggregation_by_constant_keys_on_empty_set arg Return empty result when aggregating by constant keys on empty set. --allow_distributed_ddl arg If it is set to true, then a user is allowed to executed distributed DDL queries. --allow_suspicious_codecs arg If it is set to true, allow to specify meaningless compression codecs. --allow_experimental_codecs arg If it is set to true, allow to specify experimental compression codecs (but we don't have those yet and this option does nothing). --query_profiler_real_time_period_ns arg Period for real clock timer of query profiler (in nanoseconds). Set 0 value to turn off the real clock query profiler. Recommended value is at least 10000000 (100 times a second) for single queries or 1000000000 (once a second) for cluster-wide profiling. --query_profiler_cpu_time_period_ns arg Period for CPU clock timer of query profiler (in nanoseconds). Set 0 value to turn off the CPU clock query profiler. Recommended value is at least 10000000 (100 times a second) for single queries or 1000000000 (once a second) for cluster-wide profiling. --metrics_perf_events_enabled arg If enabled, some of the perf events will be measured throughout queries' execution. --metrics_perf_events_list arg Comma separated list of perf metrics that will be measured throughout queries' execution. Empty means all events. See PerfEventInfo in sources for the available events. --opentelemetry_start_trace_probability arg Probability to start an OpenTelemetry trace for an incoming query. --opentelemetry_trace_processors arg Collect OpenTelemetry spans for processors. --prefer_column_name_to_alias arg Prefer using column names instead of aliases if possible. --prefer_global_in_and_join arg If enabled, all IN/JOIN operators will be rewritten as GLOBAL IN/JOIN. It's useful when the to-be-joined tables are only available on the initiator and we need to always scatter their data on-the-fly during distributed processing with the GLOBAL keyword. It's also useful to reduce the need to access the external sources joining external tables. --max_rows_to_read arg Limit on read rows from the most 'deep' sources. That is, only in the deepest subquery. When reading from a remote server, it is only checked on a remote server. --max_bytes_to_read arg Limit on read bytes (after decompression) from the most 'deep' sources. That is, only in the deepest subquery. When reading from a remote server, it is only checked on a remote server. --read_overflow_mode arg What to do when the limit is exceeded. --max_rows_to_read_leaf arg Limit on read rows on the leaf nodes for distributed queries. Limit is applied for local reads only excluding the final merge stage on the root node. --max_bytes_to_read_leaf arg Limit on read bytes (after decompression) on the leaf nodes for distributed queries. Limit is applied for local reads only excluding the final merge stage on the root node. --read_overflow_mode_leaf arg What to do when the leaf limit is exceeded. --max_rows_to_group_by arg --group_by_overflow_mode arg What to do when the limit is exceeded. --max_bytes_before_external_group_by arg --max_rows_to_sort arg --max_bytes_to_sort arg --sort_overflow_mode arg What to do when the limit is exceeded. --max_bytes_before_external_sort arg --max_bytes_before_remerge_sort arg In case of ORDER BY with LIMIT, when memory usage is higher than specified threshold, perform additional steps of merging blocks before final merge to keep just top LIMIT rows. --remerge_sort_lowered_memory_bytes_ratio arg If memory usage after remerge does not reduced by this ratio, remerge will be disabled. --max_result_rows arg Limit on result size in rows. Also checked for intermediate data sent from remote servers. --max_result_bytes arg Limit on result size in bytes (uncompressed). Also checked for intermediate data sent from remote servers. --result_overflow_mode arg What to do when the limit is exceeded. --max_execution_time arg --timeout_overflow_mode arg What to do when the limit is exceeded. --min_execution_speed arg Minimum number of execution rows per second. --max_execution_speed arg Maximum number of execution rows per second. --min_execution_speed_bytes arg Minimum number of execution bytes per second. --max_execution_speed_bytes arg Maximum number of execution bytes per second. --timeout_before_checking_execution_speed arg Check that the speed is not too low after the specified time has elapsed. --max_columns_to_read arg --max_temporary_columns arg --max_temporary_non_const_columns arg --max_subquery_depth arg --max_pipeline_depth arg --max_ast_depth arg Maximum depth of query syntax tree. Checked after parsing. --max_ast_elements arg Maximum size of query syntax tree in number of nodes. Checked after parsing. --max_expanded_ast_elements arg Maximum size of query syntax tree in number of nodes after expansion of aliases and the asterisk. --readonly arg 0 - everything is allowed. 1 - only read requests. 2 - only read requests, as well as changing settings, except for the 'readonly' setting. --max_rows_in_set arg Maximum size of the set (in number of elements) resulting from the execution of the IN section. --max_bytes_in_set arg Maximum size of the set (in bytes in memory) resulting from the execution of the IN section. --set_overflow_mode arg What to do when the limit is exceeded. --max_rows_in_join arg Maximum size of the hash table for JOIN (in number of rows). --max_bytes_in_join arg Maximum size of the hash table for JOIN (in number of bytes in memory). --join_overflow_mode arg What to do when the limit is exceeded. --join_any_take_last_row arg When disabled (default) ANY JOIN will take the first found row for a key. When enabled, it will take the last row seen if there are multiple rows for the same key. --join_algorithm arg Specify join algorithm. --default_max_bytes_in_join arg Maximum size of right-side table if limit is required but max_bytes_in_join is not set. --partial_merge_join_left_table_buffer_bytes arg If not 0 group left table blocks in bigger ones for left-side table in partial merge join. It uses up to 2x of specified memory per joining thread. --partial_merge_join_rows_in_right_blocks arg Split right-hand joining data in blocks of specified size. It's a portion of data indexed by min-max values and possibly unloaded on disk. --join_on_disk_max_files_to_merge arg For MergeJoin on disk set how much files it's allowed to sort simultaneously. Then this value bigger then more memory used and then less disk I/O needed. Minimum is 2. --compatibility_ignore_collation_in_create_table arg Compatibility ignore collation in create table --temporary_files_codec arg Set compression codec for temporary files (sort and join on disk). I.e. LZ4, NONE. --max_rows_to_transfer arg Maximum size (in rows) of the transmitted external table obtained when the GLOBAL IN/JOIN section is executed. --max_bytes_to_transfer arg Maximum size (in uncompressed bytes) of the transmitted external table obtained when the GLOBAL IN/JOIN section is executed. --transfer_overflow_mode arg What to do when the limit is exceeded. --max_rows_in_distinct arg Maximum number of elements during execution of DISTINCT. --max_bytes_in_distinct arg Maximum total size of state (in uncompressed bytes) in memory for the execution of DISTINCT. --distinct_overflow_mode arg What to do when the limit is exceeded. --max_memory_usage arg Maximum memory usage for processing of single query. Zero means unlimited. --memory_overcommit_ratio_denominator arg It represents soft memory limit on the user level. This value is used to compute query overcommit ratio. --max_memory_usage_for_user arg Maximum memory usage for processing all concurrently running queries for the user. Zero means unlimited. --memory_overcommit_ratio_denominator_for_user arg It represents soft memory limit on the global level. This value is used to compute query overcommit ratio. --max_untracked_memory arg Small allocations and deallocations are grouped in thread local variable and tracked or profiled only when amount (in absolute value) becomes larger than specified value. If the value is higher than 'memory_profiler_step' it will be effectively lowered to 'memory_profiler_step'. --memory_profiler_step arg Whenever query memory usage becomes larger than every next step in number of bytes the memory profiler will collect the allocating stack trace. Zero means disabled memory profiler. Values lower than a few megabytes will slow down query processing. --memory_profiler_sample_probability arg 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. Note that sampling happens only when the amount of untracked memory exceeds 'max_untracked_memory'. You may want to set 'max_untracked_memory' to 0 for extra fine grained sampling. --memory_usage_overcommit_max_wait_microseconds arg Maximum time thread will wait for memory to be freed in the case of memory overcommit. If timeout is reached and memory is not freed, exception is thrown. --max_network_bandwidth arg The maximum speed of data exchange over the network in bytes per second for a query. Zero means unlimited. --max_network_bytes arg The maximum number of bytes (compressed) to receive or transmit over the network for execution of the query. --max_network_bandwidth_for_user arg The maximum speed of data exchange over the network in bytes per second for all concurrently running user queries. Zero means unlimited. --max_network_bandwidth_for_all_users arg The maximum speed of data exchange over the network in bytes per second for all concurrently running queries. Zero means unlimited. --backup_threads arg The maximum number of threads to execute BACKUP requests. --restore_threads arg The maximum number of threads to execute RESTORE requests. --log_profile_events arg Log query performance statistics into the query_log, query_thread_log and query_views_log. --log_query_settings arg Log query settings into the query_log. --log_query_threads arg Log query threads into system.query_thread_log table. This setting have effect only when 'log_queries' is true. --log_query_views arg Log query dependent views into system.query_views_log table. This setting have effect only when 'log_queries' is true. --log_comment arg Log comment into system.query_log table and server log. It can be set to arbitrary string no longer than max_query_size. --send_logs_level arg Send server text logs with specified minimum level to client. Valid values: 'trace', 'debug', 'information', 'warning', 'error', 'fatal', 'none' --send_logs_source_regexp arg Send server text logs with specified regexp to match log source name. Empty means all sources. --enable_optimize_predicate_expression arg If it is set to true, optimize predicates to subqueries. --enable_optimize_predicate_expression_to_final_subquery arg Allow push predicate to final subquery. --allow_push_predicate_when_subquery_contains_with arg Allows push predicate when subquery contains WITH clause --low_cardinality_max_dictionary_size arg Maximum size (in rows) of shared global dictionary for LowCardinality type. --low_cardinality_use_single_dictionary_for_part arg LowCardinality type serialization setting. If is true, than will use additional keys when global dictionary overflows. Otherwise, will create several shared dictionaries. --decimal_check_overflow arg Check overflow of decimal arithmetic/comparison operations --prefer_localhost_replica arg If it's true then queries will be always sent to local replica (if it exists). If it's false then replica to send a query will be chosen between local and remote ones according to load_balancing --max_fetch_partition_retries_count arg Amount of retries while fetching partition from another host. --http_max_multipart_form_data_size arg Limit on size of multipart/form-data content. This setting cannot be parsed from URL parameters and should be set in user profile. Note that content is parsed and external tables are created in memory before start of query execution. And this is the only limit that has effect on that stage (limits on max memory usage and max execution time have no effect while reading HTTP form data). --calculate_text_stack_trace arg Calculate text stack trace in case of exceptions during query execution. This is the default. It requires symbol lookups that may slow down fuzzing tests when huge amount of wrong queries are executed. In normal cases you should not disable this option. --allow_ddl arg If it is set to true, then a user is allowed to executed DDL queries. --parallel_view_processing arg Enables pushing to attached views concurrently instead of sequentially. --enable_unaligned_array_join arg Allow ARRAY JOIN with multiple arrays that have different sizes. When this settings is enabled, arrays will be resized to the longest one. --optimize_read_in_order arg Enable ORDER BY optimization for reading data in corresponding order in MergeTree tables. --optimize_read_in_window_order arg Enable ORDER BY optimization in window clause for reading data in corresponding order in MergeTree tables. --optimize_aggregation_in_order arg Enable GROUP BY optimization for aggregating data in corresponding order in MergeTree tables. --aggregation_in_order_max_block_bytes arg Maximal size of block in bytes accumulated during aggregation in order of primary key. Lower block size allows to parallelize more final merge stage of aggregation. --read_in_order_two_level_merge_threshold arg Minimal number of parts to read to run preliminary merge step during multithread reading in order of primary key. --low_cardinality_allow_in_native_format arg Use LowCardinality type in Native format. Otherwise, convert LowCardinality columns to ordinary for select query, and convert ordinary columns to required LowCardinality for insert query. --cancel_http_readonly_queries_on_client_close arg Cancel HTTP readonly queries when a client closes the connection without waiting for response. --external_table_functions_use_nulls arg If it is set to true, external table functions will implicitly use Nullable type if needed. Otherwise NULLs will be substituted with default values. Currently supported only by 'mysql', 'postgresql' and 'odbc' table functions. --external_table_strict_query arg If it is set to true, transforming expression to local filter is forbidden for queries to external tables. --allow_hyperscan arg Allow functions that use Hyperscan library. Disable to avoid potentially long compilation times and excessive resource usage. --max_hyperscan_regexp_length arg Max length of regexp than can be used in hyperscan multi-match functions. Zero means unlimited. --max_hyperscan_regexp_total_length arg Max total length of all regexps than can be used in hyperscan multi-match functions (per every function). Zero means unlimited. --allow_simdjson arg Allow using simdjson library in 'JSON*' functions if AVX2 instructions are available. If disabled rapidjson will be used. --allow_introspection_functions arg Allow functions for introspection of ELF and DWARF for query profiling. These functions are slow and may impose security considerations. --max_partitions_per_insert_block arg Limit maximum number of partitions in single INSERTed block. Zero means unlimited. Throw exception if the block contains too many partitions. This setting is a safety threshold, because using large number of partitions is a common misconception. --max_partitions_to_read arg Limit the max number of partitions that can be accessed in one query. <= 0 means unlimited. --check_query_single_value_result arg Return check query result as single 1/0 value --allow_drop_detached arg Allow ALTER TABLE ... DROP DETACHED PART[ITION] ... queries --postgresql_connection_pool_size arg Connection pool size for PostgreSQL table engine and database engine. --postgresql_connection_pool_wait_timeout arg Connection pool push/pop timeout on empty pool for PostgreSQL table engine and database engine. By default it will block on empty pool. --postgresql_connection_pool_auto_close_connection arg Close connection before returning connection to the pool. --glob_expansion_max_elements arg Maximum number of allowed addresses (For external storages, table functions, etc). --odbc_bridge_connection_pool_size arg Connection pool size for each connection settings string in ODBC bridge. --odbc_bridge_use_connection_pooling arg Use connection pooling in ODBC bridge. If set to false, a new connection is created every time --distributed_replica_error_half_life arg Time period reduces replica error counter by 2 times. --distributed_replica_error_cap arg Max number of errors per replica, prevents piling up an incredible amount of errors if replica was offline for some time and allows it to be reconsidered in a shorter amount of time. --distributed_replica_max_ignored_errors arg Number of errors that will be ignored while choosing replicas --allow_experimental_live_view arg Enable LIVE VIEW. Not mature enough. --live_view_heartbeat_interval arg The heartbeat interval in seconds to indicate live query is alive. --max_live_view_insert_blocks_before_refresh arg Limit maximum number of inserted blocks after which mergeable blocks are dropped and query is re-executed. --allow_experimental_window_view arg Enable WINDOW VIEW. Not mature enough. --window_view_clean_interval arg The clean interval of window view in seconds to free outdated data. --window_view_heartbeat_interval arg The heartbeat interval in seconds to indicate watch query is alive. --wait_for_window_view_fire_signal_timeout arg Timeout for waiting for window view fire signal in event time processing --min_free_disk_space_for_temporary_data arg The minimum disk space to keep while writing temporary data used in external sorting and aggregation. --default_table_engine arg Default table engine used when ENGINE is not set in CREATE statement. --show_table_uuid_in_table_create_query_if_not_nil arg For tables in databases with Engine=Atomic show UUID of the table in its CREATE query. --database_atomic_wait_for_drop_and_detach_synchronously arg When executing DROP or DETACH TABLE in Atomic database, wait for table data to be finally dropped or detached. --enable_scalar_subquery_optimization arg If it is set to true, prevent scalar subqueries from (de)serializing large scalar values and possibly avoid running the same subquery more than once. --optimize_trivial_count_query arg Process trivial 'SELECT count() FROM table' query from metadata. --optimize_respect_aliases arg If it is set to true, it will respect aliases in WHERE/GROUP BY/ORDER BY, that will help with partition pruning/secondary indexes/optimize_aggr egation_in_order/optimize_read_in_order /optimize_trivial_count --mutations_sync arg Wait for synchronous execution of ALTER TABLE UPDATE/DELETE queries (mutations). 0 - execute asynchronously. 1 - wait current server. 2 - wait all replicas if they exist. --allow_experimental_lightweight_delete arg Enable lightweight DELETE mutations for mergetree tables. Work in progress --optimize_move_functions_out_of_any arg Move functions out of aggregate functions 'any', 'anyLast'. --optimize_normalize_count_variants arg Rewrite aggregate functions that semantically equals to count() as count(). --optimize_injective_functions_inside_uniq arg Delete injective functions of one argument inside uniq*() functions. --convert_query_to_cnf arg Convert SELECT query to CNF --optimize_or_like_chain arg Optimize multiple OR LIKE into multiMatchAny. This optimization should not be enabled by default, because it defies index analysis in some cases. --optimize_arithmetic_operations_in_aggregate_functions arg Move arithmetic operations out of aggregation functions --optimize_duplicate_order_by_and_distinct arg Remove duplicate ORDER BY and DISTINCT if it's possible --optimize_redundant_functions_in_order_by arg Remove functions from ORDER BY if its argument is also in ORDER BY --optimize_if_chain_to_multiif arg Replace if(cond1, then1, if(cond2, ...)) chains to multiIf. Currently it's not beneficial for numeric types. --optimize_multiif_to_if arg Replace 'multiIf' with only one condition to 'if'. --optimize_if_transform_strings_to_enum arg Replaces string-type arguments in If and Transform to enum. Disabled by default cause it could make inconsistent change in distributed query that would lead to its fail. --optimize_monotonous_functions_in_order_by arg Replace monotonous function with its argument in ORDER BY --optimize_functions_to_subcolumns arg Transform functions to subcolumns, if possible, to reduce amount of read data. E.g. 'length(arr)' -> 'arr.size0', 'col IS NULL' -> 'col.null' --optimize_using_constraints arg Use constraints for query optimization --optimize_substitute_columns arg Use constraints for column substitution --optimize_append_index arg Use constraints in order to append index condition (indexHint) --normalize_function_names arg Normalize function names to their canonical names --allow_experimental_alter_materialized_view_structure arg Allow atomic alter on Materialized views. Work in progress. --enable_early_constant_folding arg Enable query optimization where we analyze function and subqueries results and rewrite query if there're constants there --deduplicate_blocks_in_dependent_materialized_views arg Should deduplicate blocks for materialized views if the block is not a duplicate for the table. Use true to always deduplicate in dependent tables. --use_compact_format_in_distributed_parts_names arg Changes format of directories names for distributed table insert parts. --validate_polygons arg Throw exception if polygon is invalid in function pointInPolygon (e.g. self-tangent, self-intersecting). If the setting is false, the function will accept invalid polygons but may silently return wrong result. --max_parser_depth arg Maximum parser depth (recursion depth of recursive descend parser). --allow_settings_after_format_in_insert arg Allow SETTINGS after FORMAT, but note, that this is not always safe (note: this is a compatibility setting). --temporary_live_view_timeout arg Timeout after which temporary live view is deleted. --periodic_live_view_refresh arg Interval after which periodically refreshed live view is forced to refresh. --transform_null_in arg If enabled, NULL values will be matched with 'IN' operator as if they are considered equal. --allow_nondeterministic_mutations arg Allow non-deterministic functions in ALTER UPDATE/ALTER DELETE statements --lock_acquire_timeout arg How long locking request should wait before failing --materialize_ttl_after_modify arg Apply TTL for old data, after ALTER MODIFY TTL query --function_implementation arg Choose function implementation for specific target or variant (experimental). If empty enable all of them. --allow_experimental_geo_types arg Allow geo data types such as Point, Ring, Polygon, MultiPolygon --data_type_default_nullable arg Data types without NULL or NOT NULL will make Nullable --cast_keep_nullable arg CAST operator keep Nullable for result data type --cast_ipv4_ipv6_default_on_conversion_error arg CAST operator into IPv4, CAST operator into IPV6 type, toIPv4, toIPv6 functions will return default value instead of throwing exception on conversion error. --alter_partition_verbose_result arg Output information about affected parts. Currently works only for FREEZE and ATTACH commands. --allow_experimental_database_materialized_mysql arg Allow to create database with Engine=MaterializedMySQL(...). --allow_experimental_database_materialized_postgresql arg Allow to create database with Engine=MaterializedPostgreSQL(...). --system_events_show_zero_values arg Include all metrics, even with zero values --mysql_datatypes_support_level arg Which MySQL types should be converted to corresponding ClickHouse types (rather than being represented as String). Can be empty or any combination of 'decimal', 'datetime64', 'date2Date32' or 'date2String'. When empty MySQL's DECIMAL and DATETIME/TIMESTAMP with non-zero precision are seen as String on ClickHouse's side. --optimize_trivial_insert_select arg Optimize trivial 'INSERT INTO table SELECT ... FROM TABLES' query --allow_non_metadata_alters arg Allow to execute alters which affects not only tables metadata, but also data on disk --enable_global_with_statement arg Propagate WITH statements to UNION queries and all subqueries --aggregate_functions_null_for_empty arg Rewrite all aggregate functions in a query, adding -OrNull suffix to them --optimize_syntax_fuse_functions arg Not ready for production, do not use. Allow apply syntax optimisation: fuse aggregate functions --optimize_fuse_sum_count_avg arg Not ready for production, do not use. Fuse functions `sum, avg, count` with identical arguments into one `sumCount` (`optimize_syntax_fuse_functions should be enabled) --flatten_nested arg If true, columns of type Nested will be flatten to separate array columns instead of one array of tuples --asterisk_include_materialized_columns arg Include MATERIALIZED columns for wildcard query --asterisk_include_alias_columns arg Include ALIAS columns for wildcard query --optimize_skip_merged_partitions arg Skip partitions with one part with level > 0 in optimize final --optimize_on_insert arg Do the same transformation for inserted block of data as if merge was done on this block. --force_optimize_projection arg If projection optimization is enabled, SELECT queries need to use projection --async_socket_for_remote arg Asynchronously read from socket executing remote query --insert_null_as_default arg Insert DEFAULT values instead of NULL in INSERT SELECT (UNION ALL) --describe_extend_object_types arg Deduce concrete type of columns of type Object in DESCRIBE query --describe_include_subcolumns arg If true, subcolumns of all table columns will be included into result of DESCRIBE query --optimize_rewrite_sum_if_to_count_if arg Rewrite sumIf() and sum(if()) function countIf() function when logically equivalent --insert_shard_id arg If non zero, when insert into a distributed table, the data will be inserted into the shard `insert_shard_id` synchronously. Possible values range from 1 to `shards_number` of corresponding distributed table --collect_hash_table_stats_during_aggregation arg Enable collecting hash table statistics to optimize memory allocation --max_entries_for_hash_table_stats arg How many entries hash table statistics collected during aggregation is allowed to have --max_size_to_preallocate_for_aggregation arg For how many elements it is allowed to preallocate space in all hash tables in total before aggregation --kafka_disable_num_consumers_limit arg Disable limit on kafka_num_consumers that depends on the number of available CPU cores --allow_experimental_query_deduplication arg Experimental data deduplication for SELECT queries based on part UUIDs --engine_file_empty_if_not_exists arg Allows to select data from a file engine table without file --engine_file_truncate_on_insert arg Enables or disables truncate before insert in file engine tables --engine_file_allow_create_multiple_files arg Enables or disables creating a new file on each insert in file engine tables if format has suffix. --allow_experimental_database_replicated arg Allow to create databases with Replicated engine --database_replicated_initial_query_timeout_sec arg How long initial DDL query should wait for Replicated database to precess previous DDL queue entries --database_replicated_enforce_synchronous_settings arg Enforces synchronous waiting for some queries (see also database_atomic_wait_ for_drop_and_detach_synchronously, mutation_sync, replication_alter_partit ions_sync). Not recommended to enable these settings. --max_distributed_depth arg Maximum distributed query depth --database_replicated_always_detach_permanently arg Execute DETACH TABLE as DETACH TABLE PERMANENTLY if database engine is Replicated --database_replicated_allow_only_replicated_engine arg Allow to create only Replicated tables in database with engine Replicated --distributed_ddl_output_mode arg Format of distributed DDL query result --distributed_ddl_entry_format_version arg Compatibility version of distributed DDL (ON CLUSTER) queries --external_storage_max_read_rows arg Limit maximum number of rows when table with external engine should flush history data. Now supported only for MySQL table engine, database engine, dictionary and MaterializedMySQL. If equal to 0, this setting is disabled --external_storage_max_read_bytes arg Limit maximum number of bytes when table with external engine should flush history data. Now supported only for MySQL table engine, database engine, dictionary and MaterializedMySQL. If equal to 0, this setting is disabled --external_storage_connect_timeout_sec arg Connect timeout in seconds. Now supported only for MySQL --external_storage_rw_timeout_sec arg Read/write timeout in seconds. Now supported only for MySQL --union_default_mode arg Set default Union Mode in SelectWithUnion query. Possible values: empty string, 'ALL', 'DISTINCT'. If empty, query without Union Mode will throw exception. --optimize_aggregators_of_group_by_keys arg Eliminates min/max/any/anyLast aggregators of GROUP BY keys in SELECT section --optimize_group_by_function_keys arg Eliminates functions of other keys in GROUP BY section --legacy_column_name_of_tuple_literal arg List all names of element of large tuple literals in their column names instead of hash. This settings exists only for compatibility reasons. It makes sense to set to 'true', while doing rolling update of cluster from version lower than 21.7 to higher. --query_plan_enable_optimizations arg Apply optimizations to query plan --query_plan_max_optimizations_to_apply arg Limit the total number of optimizations applied to query plan. If zero, ignored. If limit reached, throw exception --query_plan_filter_push_down arg Allow to push down filter by predicate query plan step --query_plan_optimize_primary_key arg Analyze primary key using query plan (instead of AST) --regexp_max_matches_per_row arg Max matches of any single regexp per row, used to safeguard 'extractAllGroupsHorizontal' against consuming too much memory with greedy RE. --limit arg Limit on read rows from the most 'end' result for select query, default 0 means no limit length --offset arg Offset on read rows from the most 'end' result for select query --function_range_max_elements_in_block arg Maximum number of values generated by function 'range' per block of data (sum of array sizes for every row in a block, see also 'max_block_size' and 'min_insert_block_size_rows'). It is a safety threshold. --short_circuit_function_evaluation arg Setting for short-circuit function evaluation configuration. Possible values: 'enable' - use short-circuit function evaluation for functions that are suitable for it, 'disable' - disable short-circuit function evaluation, 'force_enable' - use short-circuit function evaluation for all functions. --local_filesystem_read_method arg Method of reading data from local filesystem, one of: read, pread, mmap, pread_threadpool. --remote_filesystem_read_method arg Method of reading data from remote filesystem, one of: read, threadpool. --local_filesystem_read_prefetch arg Should use prefetching when reading data from local filesystem. --remote_filesystem_read_prefetch arg Should use prefetching when reading data from remote filesystem. --read_priority arg Priority to read data from local filesystem. Only supported for 'pread_threadpool' method. --merge_tree_min_rows_for_concurrent_read_for_remote_filesystem arg If at least as many lines are read from one file, the reading can be parallelized, when reading from remote filesystem. --merge_tree_min_bytes_for_concurrent_read_for_remote_filesystem arg If at least as many bytes are read from one file, the reading can be parallelized, when reading from remote filesystem. --remote_read_min_bytes_for_seek arg Min bytes required for remote read (url, s3) to do seek, instead for read with ignore. --async_insert_threads arg Maximum number of threads to actually parse and insert data in background. Zero means asynchronous mode is disabled --async_insert arg If true, data from INSERT query is stored in queue and later flushed to table in background. Makes sense only for inserts via HTTP protocol. If wait_for_async_insert is false, INSERT query is processed almost instantly, otherwise client will wait until data will be flushed to table --wait_for_async_insert arg If true wait for processing of asynchronous insertion --wait_for_async_insert_timeout arg Timeout for waiting for processing asynchronous insertion --async_insert_max_data_size arg Maximum size in bytes of unparsed data collected per query before being inserted --async_insert_busy_timeout_ms arg Maximum time to wait before dumping collected data per query since the first data appeared --async_insert_stale_timeout_ms arg Maximum time to wait before dumping collected data per query since the last data appeared. Zero means no timeout at all --remote_fs_read_max_backoff_ms arg Max wait time when trying to read data for remote disk --remote_fs_read_backoff_max_tries arg Max attempts to read with backoff --enable_filesystem_cache arg Use cache for remote filesystem. This setting does not turn on/off cache for disks (must be done via disk config), but allows to bypass cache for some queries if intended --filesystem_cache_max_wait_sec arg Allow to wait at most this number of seconds for download of current remote_fs_buffer_size bytes, and skip cache if exceeded --enable_filesystem_cache_on_write_operations arg Write into cache on write operations. To actually work this setting requires be added to disk config too --enable_filesystem_cache_log arg Allows to record the filesystem caching log for each query --read_from_filesystem_cache_if_exists_otherwise_bypass_cache arg --enable_filesystem_cache_on_lower_level arg If read buffer supports caching inside threadpool, allow it to do it, otherwise cache outside ot threadpool. Do not use this setting, it is needed for testing --skip_download_if_exceeds_query_cache arg Skip download from remote filesystem if exceeds query cache size --max_query_cache_size arg Max remote filesystem cache size that can be used by a single query --use_structure_from_insertion_table_in_table_functions arg Use structure from insertion table instead of schema inference from data --http_max_tries arg Max attempts to read via http. --http_retry_initial_backoff_ms arg Min milliseconds for backoff, when retrying read via http --http_retry_max_backoff_ms arg Max milliseconds for backoff, when retrying read via http --force_remove_data_recursively_on_drop arg Recursively remove data on DROP query. Avoids 'Directory not empty' error, but may silently remove detached data --check_table_dependencies arg Check that DDL query (such as DROP TABLE or RENAME) will not break dependencies --use_local_cache_for_remote_storage arg Use local cache for remote storage like HDFS or S3, it's used for remote table engine only --allow_unrestricted_reads_from_keeper arg Allow unrestricted (without condition on path) reads from system.zookeeper table, can be handy, but is not safe for zookeeper --allow_deprecated_database_ordinary arg Allow to create databases with deprecated Ordinary engine --allow_deprecated_syntax_for_merge_tree arg Allow to create *MergeTree tables with deprecated engine definition syntax --schema_inference_use_cache_for_file arg Use cache in schema inference while using file table function --schema_inference_use_cache_for_s3 arg Use cache in schema inference while using s3 table function --schema_inference_use_cache_for_hdfs arg Use cache in schema inference while using hdfs table function --schema_inference_use_cache_for_url arg Use cache in schema inference while using url table function --schema_inference_cache_require_modification_time_for_url arg Use schema from cache for URL with last modification time validation (for urls with Last-Modified header) --compatibility arg Changes other settings according to provided ClickHouse version. If we know that we changed some behaviour in ClickHouse by changing some settings in some version, this compatibility setting will control these settings --additional_table_filters arg Additional filter expression which would be applied after reading from specified table. Syntax: {'table1': 'expression', 'database.table2': 'expression'} --additional_result_filter arg Additional filter expression which would be applied to query result --allow_experimental_funnel_functions arg Enable experimental functions for funnel analysis. --allow_experimental_nlp_functions arg Enable experimental functions for natural language processing. --allow_experimental_hash_functions arg Enable experimental hash functions (hashid, etc) --allow_experimental_object_type arg Allow Object and JSON data types --insert_deduplication_token arg If not empty, used for duplicate detection instead of data digest --count_distinct_optimization arg Rewrite count distinct to subquery of group by --throw_on_unsupported_query_inside_transaction arg Throw exception if unsupported query is used inside transaction --wait_changes_become_visible_after_commit_mode arg Wait for committed changes to become actually visible in the latest snapshot --implicit_transaction arg If enabled and not already inside a transaction, wraps the query inside a full transaction (begin + commit or rollback) --throw_if_no_data_to_insert arg Enables or disables empty INSERTs, enabled by default --compatibility_ignore_auto_increment_in_create_table arg Ignore AUTO_INCREMENT keyword in column declaration if true, otherwise return error. It simplifies migration from MySQL --multiple_joins_try_to_keep_original_names arg Do not add aliases to top level expression list on multiple joins rewrite --optimize_distinct_in_order arg Enable DISTINCT optimization if some columns in DISTINCT form a prefix of sorting. For example, prefix of sorting key in merge tree or ORDER BY statement --optimize_sorting_by_input_stream_properties arg Optimize sorting by sorting properties of input stream --max_memory_usage_for_all_queries arg Obsolete setting, does nothing. --multiple_joins_rewriter_version arg Obsolete setting, does nothing. --enable_debug_queries arg Obsolete setting, does nothing. --allow_experimental_database_atomic arg Obsolete setting, does nothing. --allow_experimental_bigint_types arg Obsolete setting, does nothing. --allow_experimental_window_functions arg Obsolete setting, does nothing. --handle_kafka_error_mode arg Obsolete setting, does nothing. --database_replicated_ddl_output arg Obsolete setting, does nothing. --replication_alter_columns_timeout arg Obsolete setting, does nothing. --odbc_max_field_size arg Obsolete setting, does nothing. --allow_experimental_map_type arg Obsolete setting, does nothing. --merge_tree_clear_old_temporary_directories_interval_seconds arg Obsolete setting, does nothing. --merge_tree_clear_old_parts_interval_seconds arg Obsolete setting, does nothing. --partial_merge_join_optimizations arg Obsolete setting, does nothing. --max_alter_threads arg Obsolete setting, does nothing. --allow_experimental_projection_optimization arg Obsolete setting, does nothing. --background_buffer_flush_schedule_pool_size arg Obsolete setting, does nothing. --background_pool_size arg Obsolete setting, does nothing. --background_merges_mutations_concurrency_ratio arg Obsolete setting, does nothing. --background_move_pool_size arg Obsolete setting, does nothing. --background_fetches_pool_size arg Obsolete setting, does nothing. --background_common_pool_size arg Obsolete setting, does nothing. --background_schedule_pool_size arg Obsolete setting, does nothing. --background_message_broker_schedule_pool_size arg Obsolete setting, does nothing. --background_distributed_schedule_pool_size arg Obsolete setting, does nothing. --default_database_engine arg Obsolete setting, does nothing. --format_csv_delimiter arg The character to be considered as a delimiter in CSV data. If setting with a string, a string has to have a length of 1. --format_csv_allow_single_quotes arg If it is set to true, allow strings in single quotes. --format_csv_allow_double_quotes arg If it is set to true, allow strings in double quotes. --output_format_csv_crlf_end_of_line arg If it is set true, end of line in CSV format will be \r\n instead of \n. --input_format_csv_enum_as_number arg Treat inserted enum values in CSV formats as enum indices --input_format_csv_arrays_as_nested_csv arg When reading Array from CSV, expect that its elements were serialized in nested CSV and then put into string. Example: "[""Hello"", ""world"", ""42"""" TV""]". Braces around array can be omitted. --input_format_skip_unknown_fields arg Skip columns with unknown names from input data (it works for JSONEachRow, -WithNames, -WithNamesAndTypes and TSKV formats). --input_format_with_names_use_header arg For -WithNames input formats this controls whether format parser is to assume that column data appear in the input exactly as they are specified in the header. --input_format_with_types_use_header arg For -WithNamesAndTypes input formats this controls whether format parser should check if data types from the input match data types from the header. --input_format_import_nested_json arg Map nested JSON data to nested tables (it works for JSONEachRow format). --input_format_defaults_for_omitted_fields arg For input data calculate default expressions for omitted fields (it works for JSONEachRow, -WithNames, -WithNamesAndTypes formats). --input_format_csv_empty_as_default arg Treat empty fields in CSV input as default values. --input_format_tsv_empty_as_default arg Treat empty fields in TSV input as default values. --input_format_tsv_enum_as_number arg Treat inserted enum values in TSV formats as enum indices. --input_format_null_as_default arg For text input formats initialize null fields with default values if data type of this field is not nullable --input_format_arrow_import_nested arg Allow to insert array of structs into Nested table in Arrow input format. --input_format_arrow_case_insensitive_column_matching arg Ignore case when matching Arrow columns with CH columns. --input_format_orc_import_nested arg Allow to insert array of structs into Nested table in ORC input format. --input_format_orc_row_batch_size arg Batch size when reading ORC stripes. --input_format_orc_case_insensitive_column_matching arg Ignore case when matching ORC columns with CH columns. --input_format_parquet_import_nested arg Allow to insert array of structs into Nested table in Parquet input format. --input_format_parquet_case_insensitive_column_matching arg Ignore case when matching Parquet columns with CH columns. --input_format_allow_seeks arg Allow seeks while reading in ORC/Parquet/Arrow input formats --input_format_orc_allow_missing_columns arg Allow missing columns while reading ORC input formats --input_format_parquet_allow_missing_columns arg Allow missing columns while reading Parquet input formats --input_format_arrow_allow_missing_columns arg Allow missing columns while reading Arrow input formats --input_format_hive_text_fields_delimiter arg Delimiter between fields in Hive Text File --input_format_hive_text_collection_items_delimiter arg Delimiter between collection(array or map) items in Hive Text File --input_format_hive_text_map_keys_delimiter arg Delimiter between a pair of map key/values in Hive Text File --input_format_msgpack_number_of_columns arg The number of columns in inserted MsgPack data. Used for automatic schema inference from data. --output_format_msgpack_uuid_representation arg The way how to output UUID in MsgPack format. --input_format_max_rows_to_read_for_schema_inference arg The maximum rows of data to read for automatic schema inference --input_format_csv_use_best_effort_in_schema_inference arg Use some tweaks and heuristics to infer schema in CSV format --input_format_tsv_use_best_effort_in_schema_inference arg Use some tweaks and heuristics to infer schema in TSV format --input_format_parquet_skip_columns_with_unsupported_types_in_schema_inference arg Skip columns with unsupported types while schema inference for format Parquet --input_format_parquet_max_block_size arg Max block size for parquet reader. --input_format_protobuf_skip_fields_with_unsupported_types_in_schema_inference arg Skip fields with unsupported types while schema inference for format Protobuf --input_format_capn_proto_skip_fields_with_unsupported_types_in_schema_inference arg Skip columns with unsupported types while schema inference for format CapnProto --input_format_orc_skip_columns_with_unsupported_types_in_schema_inference arg Skip columns with unsupported types while schema inference for format ORC --input_format_arrow_skip_columns_with_unsupported_types_in_schema_inference arg Skip columns with unsupported types while schema inference for format Arrow --column_names_for_schema_inference arg The list of column names to use in schema inference for formats without column names. The format: 'column1,column2,column3,...' --schema_inference_hints arg The list of column names and types to use in schema inference for formats without column names. The format: 'column1,column2,column3,...' --input_format_json_read_bools_as_numbers arg Allow to parse bools as numbers in JSON input formats --input_format_json_try_infer_numbers_from_strings arg Try to infer numbers from string fields while schema inference --input_format_try_infer_integers arg Try to infer numbers from string fields while schema inference in text formats --input_format_try_infer_dates arg Try to infer dates from string fields while schema inference in text formats --input_format_try_infer_datetimes arg Try to infer datetimes from string fields while schema inference in text formats --input_format_protobuf_flatten_google_wrappers arg Enable Google wrappers for regular non-nested columns, e.g. google.protobuf.StringValue 'str' for String column 'str'. For Nullable columns empty wrappers are recognized as defaults, and missing as nulls --output_format_protobuf_nullables_with_google_wrappers arg When serializing Nullable columns with Google wrappers, serialize default values as empty wrappers. If turned off, default and null values are not serialized --input_format_csv_skip_first_lines arg Skip specified number of lines at the beginning of data in CSV format --input_format_tsv_skip_first_lines arg Skip specified number of lines at the beginning of data in TSV format --date_time_input_format arg Method to read DateTime from text input formats. Possible values: 'basic', 'best_effort' and 'best_effort_us'. --date_time_output_format arg Method to write DateTime to text output. Possible values: 'simple', 'iso', 'unix_timestamp'. --input_format_ipv4_default_on_conversion_error arg Deserialization of IPv4 will use default values instead of throwing exception on conversion error. --input_format_ipv6_default_on_conversion_error arg Deserialization of IPV6 will use default values instead of throwing exception on conversion error. --bool_true_representation arg Text to represent bool value in TSV/CSV formats. --bool_false_representation arg Text to represent bool value in TSV/CSV formats. --input_format_values_interpret_expressions arg For Values format: if the field could not be parsed by streaming parser, run SQL parser and try to interpret it as SQL expression. --input_format_values_deduce_templates_of_expressions arg For Values format: if the field could not be parsed by streaming parser, run SQL parser, deduce template of the SQL expression, try to parse all rows using template and then interpret expression for all rows. --input_format_values_accurate_types_of_literals arg For Values format: when parsing and interpreting expressions using template, check actual type of literal to avoid possible overflow and precision issues. --input_format_avro_allow_missing_fields arg For Avro/AvroConfluent format: when field is not found in schema use default value instead of error --input_format_avro_null_as_default arg For Avro/AvroConfluent format: insert default in case of null and non Nullable column --format_avro_schema_registry_url arg For AvroConfluent format: Confluent Schema Registry URL. --output_format_json_quote_64bit_integers arg Controls quoting of 64-bit integers in JSON output format. --output_format_json_quote_denormals arg Enables '+nan', '-nan', '+inf', '-inf' outputs in JSON output format. --output_format_json_escape_forward_slashes arg Controls escaping forward slashes for string outputs in JSON output format. This is intended for compatibility with JavaScript. Don't confuse with backslashes that are always escaped. --output_format_json_named_tuples_as_objects arg Serialize named tuple columns as JSON objects. --output_format_json_array_of_rows arg Output a JSON array of all rows in JSONEachRow(Compact) format. --output_format_pretty_max_rows arg Rows limit for Pretty formats. --output_format_pretty_max_column_pad_width arg Maximum width to pad all values in a column in Pretty formats. --output_format_pretty_max_value_width arg Maximum width of value to display in Pretty formats. If greater - it will be cut. --output_format_pretty_color arg Use ANSI escape sequences to paint colors in Pretty formats --output_format_pretty_grid_charset arg Charset for printing grid borders. Available charsets: ASCII, UTF-8 (default one). --output_format_parquet_row_group_size arg Row group size in rows. --output_format_parquet_string_as_string arg Use Parquet String type instead of Binary for String columns. --output_format_avro_codec arg Compression codec used for output. Possible values: 'null', 'deflate', 'snappy'. --output_format_avro_sync_interval arg Sync interval in bytes. --output_format_avro_string_column_pattern arg For Avro format: regexp of String columns to select as AVRO string. --output_format_avro_rows_in_file arg Max rows in a file (if permitted by storage) --output_format_tsv_crlf_end_of_line arg If it is set true, end of line in TSV format will be \r\n instead of \n. --format_csv_null_representation arg Custom NULL representation in CSV format --format_tsv_null_representation arg Custom NULL representation in TSV format --output_format_decimal_trailing_zeros arg Output trailing zeros when printing Decimal values. E.g. 1.230000 instead of 1.23. --input_format_allow_errors_num arg Maximum absolute amount of errors while reading text formats (like CSV, TSV). In case of error, if at least absolute or relative amount of errors is lower than corresponding value, will skip until next line and continue. --input_format_allow_errors_ratio arg Maximum relative amount of errors while reading text formats (like CSV, TSV). In case of error, if at least absolute or relative amount of errors is lower than corresponding value, will skip until next line and continue. --format_schema arg Schema identifier (used by schema-based formats) --format_template_resultset arg Path to file which contains format string for result set (for Template format) --format_template_row arg Path to file which contains format string for rows (for Template format) --format_template_rows_between_delimiter arg Delimiter between rows (for Template format) --format_custom_escaping_rule arg Field escaping rule (for CustomSeparated format) --format_custom_field_delimiter arg Delimiter between fields (for CustomSeparated format) --format_custom_row_before_delimiter arg Delimiter before field of the first column (for CustomSeparated format) --format_custom_row_after_delimiter arg Delimiter after field of the last column (for CustomSeparated format) --format_custom_row_between_delimiter arg Delimiter between rows (for CustomSeparated format) --format_custom_result_before_delimiter arg Prefix before result set (for CustomSeparated format) --format_custom_result_after_delimiter arg Suffix after result set (for CustomSeparated format) --format_regexp arg Regular expression (for Regexp format) --format_regexp_escaping_rule arg Field escaping rule (for Regexp format) --format_regexp_skip_unmatched arg Skip lines unmatched by regular expression (for Regexp format) --output_format_enable_streaming arg Enable streaming in output formats that support it. --output_format_write_statistics arg Write statistics about read rows, bytes, time elapsed in suitable output formats. --output_format_pretty_row_numbers arg Add row numbers before each row for pretty output format --insert_distributed_one_random_shard arg If setting is enabled, inserting into distributed table will choose a random shard to write when there is no sharding key --exact_rows_before_limit arg When enabled, ClickHouse will provide exact value for rows_before_limit_at_le ast statistic, but with the cost that the data before limit will have to be read completely --cross_to_inner_join_rewrite arg Use inner join instead of comma/cross join if there're joining expressions in the WHERE section. Values: 0 - no rewrite, 1 - apply if possible for comma/cross, 2 - force rewrite all comma joins, cross - if possible --output_format_arrow_low_cardinality_as_dictionary arg Enable output LowCardinality type as Dictionary Arrow type --output_format_arrow_string_as_string arg Use Arrow String type instead of Binary for String columns --output_format_orc_string_as_string arg Use ORC String type instead of Binary for String columns --format_capn_proto_enum_comparising_mode arg How to map ClickHouse Enum and CapnProto Enum --input_format_mysql_dump_table_name arg Name of the table in MySQL dump from which to read data --input_format_mysql_dump_map_column_names arg Match columns from table in MySQL dump and columns from ClickHouse table by names --output_format_sql_insert_max_batch_size arg The maximum number of rows in one INSERT statement. --output_format_sql_insert_table_name arg The name of table in the output INSERT query --output_format_sql_insert_include_column_names arg Include column names in INSERT query --output_format_sql_insert_use_replace arg Use REPLACE statement instead of INSERT --output_format_sql_insert_quote_names arg Quote column names with '`' characters Example printing memory used by each Unix user: ps aux | tail -n +2 | awk '{ printf("%s\t%s\n", $1, $4) }' | clickhouse-local -S "user String, mem Float64" -q "SELECT user, round(sum(mem), 2) as mem_total FROM table GROUP BY user ORDER BY mem_total DESC FORMAT PrettyCompact"