allow_experimental_* session settings

These settings are available in system.settings and are autogenerated from source.

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allow_experimental_analyzer

Aliases: enable_analyzer Obsolete since v26.9: the analyzer cannot be disabled anymore. The analyzer is the query analysis and planning infrastructure that has been the default since v24.3. In v26.9 the old query analysis was deprecated and this setting was frozen at its only supported value, 1: an attempt to set it to 0 is rejected, and the compatibility setting no longer reverts it. Remove enable_analyzer = 0 from queries, session settings, settings profiles and client configurations. To compare the behaviour or the performance of a query with the old query analysis, use a ClickHouse version older than v26.9.

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allow_experimental_cleanup_old_data_files_compaction

Allow to clean up old data files during Iceberg compaction.

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allow_experimental_database_hms_catalog

Allow experimental database engine DataLakeCatalog with catalog_type = ‘hms’

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allow_experimental_database_materialized_postgresql

Allow to create database with Engine=MaterializedPostgreSQL(…).

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allow_experimental_database_paimon_rest_catalog

Allow experimental database engine DataLakeCatalog with catalog_type = ‘paimon_rest’

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allow_experimental_eval_table_function

Enable experimental table function eval.

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allow_experimental_expire_snapshots

Allow to execute experimental Iceberg command ALTER TABLE ... EXECUTE expire_snapshots.

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allow_experimental_hash_functions

Enable experimental hash functions

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allow_experimental_iceberg_compaction

Allow to explicitly use ‘OPTIMIZE’ for iceberg tables.

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allow_experimental_kusto_dialect

Enable the Kusto Query Language (KQL) dialect - an alternative to SQL.

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allow_experimental_nlp_functions

Enable experimental functions for natural language processing.

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allow_experimental_object_storage_queue_hive_partitioning

Allow to use hive partitioning with S3Queue/AzureQueue engines

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allow_experimental_paimon_storage_engine

Allow to create tables with Paimon* table engines.

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allow_experimental_parallel_reading_from_replicas

Aliases: enable_parallel_replicas Use up to max_parallel_replicas the number of replicas from each shard for SELECT query execution. Reading is parallelized and coordinated dynamically. 0 - disabled, 1 - enabled, silently disable them in case of failure, 2 - enabled, throw an exception in case of failure

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allow_experimental_polyglot_dialect

Enable polyglot SQL transpiler - transpiles SQL from 30+ dialects (MySQL, PostgreSQL, SQLite, Snowflake, DuckDB, etc.) into ClickHouse SQL.

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allow_experimental_prql_dialect

Enable PRQL - an alternative to SQL.

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allow_experimental_ytsaurus_dictionary_source

Experimental dictionary source for integration with YTsaurus.

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allow_experimental_ytsaurus_table_engine

Experimental table engine for integration with YTsaurus.

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allow_experimental_ytsaurus_table_function

Experimental table engine for integration with YTsaurus.