Beta and experimental features

ClickHouse has beta and experimental features. This documentation page discusses definition.

Because ClickHouse is open-source, it receives many contributions not only from ClickHouse employees but also from the community. These contributions are often developed at different speeds; certain features may require a lengthy prototyping phase or more time for sufficient community feedback and iteration to be considered generally available (GA).

Due to the uncertainty of when features are classified as generally available, we delineate features into two categories: Beta and Experimental.

Beta features are officially supported by the ClickHouse team. Experimental features are early prototypes driven by either the ClickHouse team or the community and aren’t officially supported.

The sections below explicitly describe the properties of Beta and Experimental features:

Beta features

• Under active development to make them generally available (GA)
• Main known issues can be tracked on GitHub
• Functionality may change in the future
• Possibly enabled in ClickHouse Cloud
• The ClickHouse team supports beta features

You can find below the features considered Beta in ClickHouse Cloud and are available for use in your ClickHouse Cloud Services.

Note: please be sure to be using a current version of the ClickHouse compatibility setting to be using a recently introduced feature.

Experimental features

• May never become GA
• May be removed
• Can introduce breaking changes
• Functionality may change in the feature
• Need to be deliberately enabled
• The ClickHouse team doesn’t support experimental features
• May lack important functionality and documentation
• Can’t be enabled in the cloud

Please note: no additional experimental features are allowed to be enabled in ClickHouse Cloud other than those listed above as Beta.

Beta settings

Name	Default
geotoh3_argument_order	lat_lon
enable_lightweight_update	1
allow_experimental_correlated_subqueries	1
parallel_replicas_count	0
parallel_replica_offset	0
parallel_replicas_custom_key	“
parallel_replicas_custom_key_range_lower	0
parallel_replicas_custom_key_range_upper	0
parallel_replicas_filter_pushdown	0
parallel_replicas_allow_view_over_mergetree	0
allow_experimental_database_iceberg	0
allow_experimental_database_unity_catalog	0
allow_experimental_database_glue_catalog	0
session_timezone	“
low_priority_query_wait_time_ms	1000
allow_experimental_delta_kernel_rs	1
allow_insert_into_iceberg	0
enable_join_runtime_filters	1

Experimental settings

Name	Default
query_plan_optimize_join_order_randomize	0
enable_join_transitive_predicates	0
ast_fuzzer_runs	0
ast_fuzzer_any_query	0
allow_fuzz_query_functions	0
enable_materialized_cte	0
analyzer_inline_views	0
allow_experimental_kafka_offsets_storage_in_keeper	0
allow_experimental_delta_lake_writes	0
automatic_parallel_replicas_mode	0
automatic_parallel_replicas_min_bytes_per_replica	1048576
distributed_index_analysis	0
allow_experimental_materialized_postgresql_table	0
allow_experimental_funnel_functions	0
allow_experimental_nlp_functions	0
allow_experimental_hash_functions	0
allow_experimental_time_series_table	0
allow_experimental_unique_key	0
allow_experimental_codecs	0
throw_on_unsupported_query_inside_transaction	1
wait_changes_become_visible_after_commit_mode	wait_unknown
implicit_transaction	0
grace_hash_join_initial_buckets	1
grace_hash_join_max_buckets	1024
join_to_sort_minimum_perkey_rows	40
join_to_sort_maximum_table_rows	10000
allow_experimental_join_right_table_sorting	0
allow_experimental_json_lazy_type_hints	0
allow_experimental_window_view	0
window_view_clean_interval	60
window_view_heartbeat_interval	15
wait_for_window_view_fire_signal_timeout	10
stop_refreshable_materialized_views_on_startup	0
allow_experimental_database_materialized_postgresql	0
allow_experimental_nullable_tuple_type	0
allow_experimental_query_deduplication	0
allow_experimental_database_hms_catalog	0
allow_experimental_kusto_dialect	0
allow_experimental_prql_dialect	0
allow_experimental_polyglot_dialect	0
polyglot_dialect	“
enable_adaptive_memory_spill_scheduler	0
allow_experimental_cleanup_old_data_files_compaction	0
allow_experimental_iceberg_compaction	0
allow_iceberg_remove_orphan_files	0
iceberg_orphan_files_older_than_seconds	259200
allow_experimental_expire_snapshots	0
write_full_path_in_iceberg_metadata	0
iceberg_metadata_compression_method	“
make_distributed_plan	0
distributed_plan_execute_locally	0
distributed_plan_default_shuffle_join_bucket_count	8
distributed_plan_default_reader_bucket_count	8
distributed_plan_force_exchange_kind	“
distributed_plan_max_rows_to_broadcast	20000
distributed_plan_prefer_replicas_over_workers	0
allow_experimental_ytsaurus_table_engine	0
allow_experimental_ytsaurus_table_function	0
allow_experimental_ytsaurus_dictionary_source	0
distributed_plan_force_shuffle_aggregation	0
join_runtime_filter_exact_values_limit	10000
join_runtime_bloom_filter_bytes	524288
join_runtime_bloom_filter_hash_functions	3
join_runtime_filter_pass_ratio_threshold_for_disabling	0.7
join_runtime_filter_blocks_to_skip_before_reenabling	30
join_runtime_bloom_filter_max_ratio_of_set_bits	0.7
rewrite_in_to_join	0
allow_experimental_time_series_aggregate_functions	0
promql_database	“
promql_table	“
promql_evaluation_time	auto
allow_experimental_alias_table_engine	0
allow_experimental_paimon_storage_engine	0
paimon_target_snapshot_id	-1
max_consume_snapshots	0
use_paimon_partition_pruning	0
allow_experimental_object_storage_queue_hive_partitioning	0
query_plan_optimize_join_order_algorithm	greedy
allow_experimental_database_paimon_rest_catalog	0
webassembly_udf_max_fuel	100000
webassembly_udf_max_memory	134217728
webassembly_udf_max_input_block_size	0
webassembly_udf_max_instances	32
allow_experimental_ai_functions	0
ai_function_request_timeout_sec	60
ai_function_max_retries	0
ai_function_retry_initial_delay_ms	1000
ai_function_throw_on_error	1
ai_function_max_input_tokens_per_query	1000000
ai_function_max_output_tokens_per_query	500000
ai_function_max_api_calls_per_query	0
ai_function_throw_on_quota_exceeded	1
allow_commit_order_projection	0
allow_experimental_replacing_merge_with_cleanup	0
allow_experimental_reverse_key	0
allow_remote_fs_zero_copy_replication	0
distributed_index_analysis_min_indexes_bytes_to_activate	1073741824
distributed_index_analysis_min_parts_to_activate	10
enable_replacing_merge_with_cleanup_for_min_age_to_force_merge	0
force_read_through_cache_for_merges	0
merge_selector_algorithm	Simple
merge_selector_enable_heuristic_to_lower_max_parts_to_merge_at_once	0
merge_selector_heuristic_to_lower_max_parts_to_merge_at_once_exponent	5
notify_newest_block_number	0
part_moves_between_shards_delay_seconds	30
part_moves_between_shards_enable	0
remote_fs_zero_copy_path_compatible_mode	0
remote_fs_zero_copy_zookeeper_path	/clickhouse/zero_copy
remove_rolled_back_parts_immediately	1
shared_merge_tree_virtual_parts_discovery_batch	1