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 three categories: Beta, Experimental, and Private preview.

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. Private preview features are on a clear path to general availability but still have limited applicability and are not recommended for production use.

The sections below explicitly describe the properties of Beta, Experimental, and Private preview 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.

Private preview features

• On a clear path to general availability (GA)
• Applicability is still limited
• Not recommended for production use
• Functionality may change in the future
• Need to be deliberately enabled

Beta settings

Name	Default
compute_exact_num_defaults_for_sparse_columns	1
packed_skip_index_max_bytes	1048576
framing_output_format	None
enable_join_transitive_predicates	1
geotoh3_argument_order	lat_lon
optimize_trivial_count_with_sparsity_filter	1
enable_lightweight_update	1
allow_experimental_correlated_subqueries	1
allow_experimental_delta_lake_writes	0
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_nullable_tuple_type	0
ai_function_request_timeout_sec	60
ai_function_max_retries	1
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	1000
ai_function_throw_on_quota_exceeded	1
ai_function_embedding_max_batch_size	100
ai_function_text_default_credentials	“
ai_function_embedding_default_credentials	“
ai_function_allow_insecure_endpoint	0
enable_alp_codec	0
allow_delta_kernel_rs	1
allow_insert_into_iceberg	0
cascades_aggregation_pushdown	1
enable_join_runtime_filters	1

Experimental settings

Name	Default
allow_commit_order_projection	0
allow_experimental_replacing_merge_with_cleanup	0
allow_experimental_text_index_phrase_search	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_adaptive_codec_selection	0
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_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
use_reader_executor	0
reader_executor_use_long_connections	0
reader_executor_min_bytes_for_seek	2097152
reader_executor_max_tail_for_drain	1048576
reader_executor_window_size	4194304
reader_executor_block_size	1048576
group_by_top_k_optimization_observation_rows	65536
query_plan_optimize_join_order_max_searched_plans	100000
query_plan_optimize_join_order_randomize	0
ast_fuzzer_runs	0
ast_fuzzer_any_query	0
ast_fuzzer_oracle	0
allow_fuzz_query_functions	0
reserve_memory	0
resumable_backup_from_snapshot	0
allow_experimental_url_wildcard_from_index_pages	0
enable_materialized_cte	0
analyzer_inline_views	0
allow_experimental_kafka_offsets_storage_in_keeper	0
automatic_parallel_replicas_mode	0
automatic_parallel_replicas_min_bytes_per_replica	1048576
parallel_replicas_plan_based	0
parallel_replicas_allow_merge_tables	0
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
time_series_prefer_recent_samples_table	1
unique_key_max_encoded_size	256
unique_key_probe_implementation	auto
allow_experimental_unique_key	0
enable_quantized_codec	0
enable_sz3_codec	0
enable_zxc_codec	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
enable_streaming_queries	0
stop_refreshable_materialized_views_on_startup	0
allow_experimental_database_materialized_postgresql	0
allow_experimental_database_hms_catalog	0
allow_experimental_kusto_dialect	0
allow_experimental_prql_dialect	0
allow_experimental_polyglot_dialect	0
enable_json_ast_dialect	0
polyglot_dialect	“
enable_adaptive_memory_spill_scheduler	0
allow_experimental_cleanup_old_data_files_compaction	0
allow_experimental_iceberg_compaction	0
iceberg_manifest_min_count_to_compact	30
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_workers_num	0
distributed_plan_workers_provisioning_timeout_ms	10000
distributed_plan_force_exchange_kind	“
distributed_plan_max_rows_to_broadcast	20000
distributed_plan_read_in_order	0
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
enable_cascades_optimizer	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
join_runtime_filter_min_probe_rows	1000
enable_join_runtime_filters_index_analysis	0
rewrite_in_to_join	0
allow_experimental_time_series_aggregate_functions	0
promql_database	“
promql_table	“
promql_evaluation_time	auto
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
query_plan_optimize_join_order_use_cd_a_conflict_detector	0
query_plan_optimize_join_order_use_cd_c_conflict_detector	0
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_eval_table_function	0