**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(UInt64, partial_merge_join_rows_in_right_blocks, 65536, "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.", 0) \
    M(UInt64, join_on_disk_max_files_to_merge, 64, "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.", 0) \
    M(UInt64, max_rows_in_set_to_optimize_join, 100'000, "Maximal size of the set to filter joined tables by each other row sets before joining. 0 - disable.", 0) \
    \
    M(Bool, compatibility_ignore_collation_in_create_table, true, "Compatibility ignore collation in create table", 0) \
    \
    M(String, temporary_files_codec, "LZ4", "Set compression codec for temporary files (sort and join on disk). I.e. LZ4, NONE.", 0) \
    \
    M(UInt64, max_rows_to_transfer, 0, "Maximum size (in rows) of the transmitted external table obtained when the GLOBAL IN/JOIN section is executed.", 0) \
    M(UInt64, max_bytes_to_transfer, 0, "Maximum size (in uncompressed bytes) of the transmitted external table obtained when the GLOBAL IN/JOIN section is executed.", 0) \
    M(OverflowMode, transfer_overflow_mode, OverflowMode::THROW, "What to do when the limit is exceeded.", 0) \
    \
    M(UInt64, max_rows_in_distinct, 0, "Maximum number of elements during execution of DISTINCT.", 0) \
    M(UInt64, max_bytes_in_distinct, 0, "Maximum total size of state (in uncompressed bytes) in memory for the execution of DISTINCT.", 0) \
    M(OverflowMode, distinct_overflow_mode, OverflowMode::THROW, "What to do when the limit is exceeded.", 0) \
    \
    M(UInt64, max_memory_usage, 0, "Maximum memory usage for processing of single query. Zero means unlimited.", 0) \
    M(UInt64, memory_overcommit_ratio_denominator, 1_GiB, "It represents soft memory limit on the user level. This value is used to compute query overcommit ratio.", 0) \
    M(UInt64, max_memory_usage_for_user, 0, "Maximum memory usage for processing all concurrently running queries for the user. Zero means unlimited.", 0) \
    M(UInt64, memory_overcommit_ratio_denominator_for_user, 1_GiB, "It represents soft memory limit on the global level. This value is used to compute query overcommit ratio.", 0) \
    M(UInt64, max_untracked_memory, (4 * 1024 * 1024), "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'.", 0) \
    M(UInt64, memory_profiler_step, (4 * 1024 * 1024), "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.", 0) \
    M(Float, memory_profiler_sample_probability, 0., "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.", 0) \
    \
    M(UInt64, memory_usage_overcommit_max_wait_microseconds, 5'000'000, "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.", 0) \
    \
    M(UInt64, max_network_bandwidth, 0, "The maximum speed of data exchange over the network in bytes per second for a query. Zero means unlimited.", 0) \
    M(UInt64, max_network_bytes, 0, "The maximum number of bytes (compressed) to receive or transmit over the network for execution of the query.", 0) \
    M(UInt64, max_network_bandwidth_for_user, 0, "The maximum speed of data exchange over the network in bytes per second for all concurrently running user queries. Zero means unlimited.", 0)\
    M(UInt64, max_network_bandwidth_for_all_users, 0, "The maximum speed of data exchange over the network in bytes per second for all concurrently running queries. Zero means unlimited.", 0) \