**Use case**

If FixedString is used with more than 256 bytes in size, it is suspicious and most likely indicates misusage.
Forbid this by default and add a setting to override it; ATTACH queries should allow creating tables nevertheless.

See also: `allow_suspicious_low_cardinality_types`.

M(Seconds, tcp_keep_alive_timeout, 290 /* less than DBMS_DEFAULT_RECEIVE_TIMEOUT_SEC */, "The time in seconds the connection needs to remain idle before TCP starts sending keepalive probes", 0) \
    M(Milliseconds, hedged_connection_timeout_ms, 100, "Connection timeout for establishing connection with replica for Hedged requests", 0) \
    M(Milliseconds, receive_data_timeout_ms, 2000, "Connection timeout for receiving first packet of data or packet with positive progress from replica", 0) \
    M(Bool, use_hedged_requests, true, "Use hedged requests for distributed queries", 0) \
    M(Bool, allow_changing_replica_until_first_data_packet, false, "Allow HedgedConnections to change replica until receiving first data packet", 0) \
    M(Milliseconds, queue_max_wait_ms, 0, "The wait time in the request queue, if the number of concurrent requests exceeds the maximum.", 0) \
    M(Milliseconds, connection_pool_max_wait_ms, 0, "The wait time when the connection pool is full.", 0) \
    M(Milliseconds, replace_running_query_max_wait_ms, 5000, "The wait time for running query with the same query_id to finish when setting 'replace_running_query' is active.", 0) \
    M(Milliseconds, kafka_max_wait_ms, 5000, "The wait time for reading from Kafka before retry.", 0) \
    M(Milliseconds, rabbitmq_max_wait_ms, 5000, "The wait time for reading from RabbitMQ before retry.", 0) \
    M(UInt64, poll_interval, DBMS_DEFAULT_POLL_INTERVAL, "Block at the query wait loop on the server for the specified number of seconds.", 0) \
    M(UInt64, idle_connection_timeout, 3600, "Close idle TCP connections after specified number of seconds.", 0) \
    M(UInt64, distributed_connections_pool_size, 1024, "Maximum number of connections with one remote server in the pool.", 0) \
    M(UInt64, connections_with_failover_max_tries, DBMS_CONNECTION_POOL_WITH_FAILOVER_DEFAULT_MAX_TRIES, "The maximum number of attempts to connect to replicas.", 0) \
    M(UInt64, s3_min_upload_part_size, 16*1024*1024, "The minimum size of part to upload during multipart upload to S3.", 0) \
    M(UInt64, s3_upload_part_size_multiply_factor, 2, "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.", 0) \
    M(UInt64, s3_upload_part_size_multiply_parts_count_threshold, 1000, "Each time this number of parts was uploaded to S3 s3_min_upload_part_size multiplied by s3_upload_part_size_multiply_factor.", 0) \
    M(UInt64, s3_max_single_part_upload_size, 32*1024*1024, "The maximum size of object to upload using singlepart upload to S3.", 0) \
    M(UInt64, s3_max_single_read_retries, 4, "The maximum number of retries during single S3 read.", 0) \
    M(UInt64, s3_max_unexpected_write_error_retries, 4, "The maximum number of retries in case of unexpected errors during S3 write.", 0) \
    M(UInt64, s3_max_redirects, 10, "Max number of S3 redirects hops allowed.", 0) \
    M(UInt64, s3_max_connections, 1024, "The maximum number of connections per server.", 0) \
    M(Bool, s3_truncate_on_insert, false, "Enables or disables truncate before insert in s3 engine tables.", 0) \
    M(Bool, s3_create_new_file_on_insert, false, "Enables or disables creating a new file on each insert in s3 engine tables", 0) \
    M(Bool, s3_check_objects_after_upload, false, "Check each uploaded object to s3 with head request to be sure that upload was successful", 0) \
    M(Bool, s3_allow_parallel_part_upload, true, "Use multiple threads for s3 multipart upload. It may lead to slightly higher memory usage", 0) \
    M(Bool, enable_s3_requests_logging, false, "Enable very explicit logging of S3 requests. Makes sense for debug only.", 0) \
    M(UInt64, hdfs_replication, 0, "The actual number of replications can be specified when the hdfs file is created.", 0) \
    M(Bool, hdfs_truncate_on_insert, false, "Enables or disables truncate before insert in s3 engine tables", 0) \
    M(Bool, hdfs_create_new_file_on_insert, false, "Enables or disables creating a new file on each insert in hdfs engine tables", 0) \