> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-postgresql-tls-support.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# allow_experimental_* 会话设置

> ClickHouse 中 allow_experimental_* 自动生成组里的会话设置。

export const VersionHistory = ({rows = []}) => {
  if (rows.length === 0) {
    return null;
  }
  const headers = ["版本", "默认值", "注释"];
  const border = "1px solid rgba(128, 128, 128, 0.3)";
  const cell = {
    border,
    padding: "0.25rem 0.5rem",
    textAlign: "start",
    verticalAlign: "top"
  };
  return <details className="not-prose" style={{
    border,
    borderRadius: "0.5rem",
    margin: "0.5rem 0",
    padding: "0.5rem 0.75rem",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <summary style={{
    cursor: "pointer",
    fontWeight: 600,
    opacity: 0.72
  }}>
        版本历史
      </summary>
      <table style={{
    borderCollapse: "collapse",
    width: "100%",
    margin: "0.5rem 0 0"
  }}>
        <thead>
          <tr>
            {headers.map(header => <th key={header} style={{
    ...cell,
    fontWeight: 600,
    opacity: 0.72
  }}>
                {header}
              </th>)}
          </tr>
        </thead>
        <tbody>
          {rows.map((row, row_index) => <tr key={row.id ?? row_index}>
              {(row.items ?? []).map((item, item_index) => <td key={item_index} style={{
    ...cell,
    overflowWrap: "anywhere"
  }}>
                  {item?.label}
                </td>)}
            </tr>)}
        </tbody>
      </table>
    </details>;
};

export const SettingsInfoBlock = ({type, default_value, changeable_without_restart}) => {
  return <div className="not-prose" style={{
    display: "flex",
    flexWrap: "wrap",
    alignItems: "baseline",
    columnGap: "0.5rem",
    rowGap: "0.125rem",
    margin: "0.375rem 0",
    fontSize: "0.8125rem",
    lineHeight: "1.125rem"
  }}>
      <div style={{
    fontWeight: 600,
    opacity: 0.72
  }}>类型</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{type}</div>
      <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>默认值</div>
      <div style={{
    overflowWrap: "anywhere"
  }}>{default_value}</div>
      {changeable_without_restart && <div style={{
    fontWeight: 600,
    opacity: 0.72,
    marginInlineStart: "0.5rem"
  }}>
          无需重启即可更改
        </div>}
      {changeable_without_restart && <div style={{
    overflowWrap: "anywhere"
  }}>
          {changeable_without_restart}
        </div>}
    </div>;
};

export const BetaBadge = ({link, galaxyTrack, galaxyEvent}) => {
  if (link) {
    return <a href={link} target="_blank" rel="noopener noreferrer" className="betaBadge" onClick={galaxyTrack && galaxyEvent ? galaxyOnClick(galaxyEvent) : undefined}>
                <span>Beta</span>
            </a>;
  }
  return <a href="/docs/beta-and-experimental-features#beta-features" className="betaBadge">
            <span>Beta 版功能</span>
        </a>;
};

export const ExperimentalBadge = () => {
  return <a href="/docs/beta-and-experimental-features#experimental-features" className="experimentalBadge">
            <div className="experimentalIcon">
            <svg width="16" height="16" viewBox="0 0 16 16" fill="none" xmlns="http://www.w3.org/2000/svg">
                <path strokeWidth="1.25" d="M5.5 2H10.5" stroke="currentColor" strokeLinecap="round" strokeLinejoin="round" />
                <path strokeWidth="1.25" d="M9.50015 2V6.19625L13.4283 12.7425C13.4738 12.8183 13.4985 12.9049 13.4996 12.9934C13.5008 13.0818 13.4785 13.169 13.435 13.246C13.3914 13.323 13.3283 13.3871 13.2519 13.4317C13.1755 13.4764 13.0886 13.4999 13.0002 13.5H3.00015C2.91164 13.5 2.8247 13.4766 2.74822 13.432C2.67174 13.3874 2.60847 13.3233 2.56487 13.2463C2.52126 13.1693 2.49889 13.082 2.50004 12.9935C2.50119 12.905 2.52582 12.8184 2.5714 12.7425L6.50015 6.19625V2" stroke="currentColor" strokeLinecap="round" strokeLinejoin="round" />
                <path strokeWidth="1.25" d="M4.47656 9.56754C5.30344 9.41254 6.47656 9.47942 7.99969 10.25C10.0153 11.2707 11.4216 11.0569 12.2184 10.7282" stroke="currentColor" strokeLinecap="round" strokeLinejoin="round" />
            </svg>
        </div>
            Experimental 功能
        </a>;
};

这些设置可在 [system.settings](/zh/reference/system-tables/settings) 中查看，由 [源代码](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp) 自动生成。

<div id="allow_experimental_ai_functions">
  ## allow\_experimental\_ai\_functions
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

启用实验性 AI 函数 (例如 `aiGenerateContent`) 。这些函数会向 AI 提供商发起外部 HTTP 调用。

<div id="allow_experimental_analyzer">
  ## allow\_experimental\_analyzer
</div>

**别名**: `enable_analyzer`

<SettingsInfoBlock type="Bool" default_value="1" />

允许启用 analyzer。

<div id="allow_experimental_cleanup_old_data_files_compaction">
  ## allow\_experimental\_cleanup\_old\_data\_files\_compaction
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许在 Iceberg 合并整理期间清理旧数据文件。

<div id="allow_experimental_codecs">
  ## allow\_experimental\_codecs
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

如果将其设置为 true，则允许指定 Experimental 压缩编解码器 (不过目前还没有此类编解码器，因此此选项实际上不起作用) 。

<div id="allow_experimental_correlated_subqueries">
  ## allow\_experimental\_correlated\_subqueries
</div>

<BetaBadge />

<SettingsInfoBlock type="Bool" default_value="1" />

允许执行关联子查询。

<div id="allow_experimental_database_glue_catalog">
  ## allow\_experimental\_database\_glue\_catalog
</div>

<BetaBadge />

**别名**: `allow_database_glue_catalog`

<SettingsInfoBlock type="Bool" default_value="0" />

启用 catalog\_type = 'glue' 的 Experimental 数据库引擎 DataLakeCatalog

Cloud 默认值：`1`。

<div id="allow_experimental_database_hms_catalog">
  ## allow\_experimental\_database\_hms\_catalog
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许使用 catalog\_type = 'hms' 的Experimental数据库引擎 DataLakeCatalog

<div id="allow_experimental_database_iceberg">
  ## allow\_experimental\_database\_iceberg
</div>

<BetaBadge />

**别名**: `allow_database_iceberg`

<SettingsInfoBlock type="Bool" default_value="0" />

允许使用 `catalog_type = 'iceberg'` 的Experimental DataLakeCatalog 数据库引擎

Cloud 默认值：`1`。

<div id="allow_experimental_database_materialized_postgresql">
  ## allow\_experimental\_database\_materialized\_postgresql
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许创建使用 Engine=MaterializedPostgreSQL(...) 的 database。

<div id="allow_experimental_database_paimon_rest_catalog">
  ## allow\_experimental\_database\_paimon\_rest\_catalog
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许使用 catalog\_type = 'paimon\_rest' 的Experimental数据库引擎 DataLakeCatalog

<div id="allow_experimental_database_unity_catalog">
  ## allow\_experimental\_database\_unity\_catalog
</div>

<BetaBadge />

**别名**: `allow_database_unity_catalog`

<SettingsInfoBlock type="Bool" default_value="0" />

允许使用 catalog\_type = 'unity' 的Experimental数据库引擎 DataLakeCatalog

Cloud 默认值：`1`。

<div id="allow_experimental_delta_kernel_rs">
  ## allow\_experimental\_delta\_kernel\_rs
</div>

<BetaBadge />

<SettingsInfoBlock type="Bool" default_value="1" />

允许使用Experimental的 delta-kernel-rs 实现。

<div id="allow_experimental_delta_lake_writes">
  ## allow\_experimental\_delta\_lake\_writes
</div>

<BetaBadge />

**别名**: `allow_delta_lake_writes`

<SettingsInfoBlock type="Bool" default_value="0" />

启用 delta-kernel 写入功能。

<div id="allow_experimental_eval_table_function">
  ## allow\_experimental\_eval\_table\_function
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

启用 Experimental 表函数 `eval`。

<div id="allow_experimental_expire_snapshots">
  ## allow\_experimental\_expire\_snapshots
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许执行Experimental的 Iceberg 命令 `ALTER TABLE ... EXECUTE expire_snapshots`。

<div id="allow_experimental_funnel_functions">
  ## allow\_experimental\_funnel\_functions
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

启用用于漏斗分析的 Experimental 函数。

<div id="allow_experimental_geo_types_in_iceberg">
  ## allow\_experimental\_geo\_types\_in\_iceberg
</div>

<SettingsInfoBlock type="Bool" default_value="0" />

允许将 Iceberg `geometry` 和 `geography` 字段类型解析为 ClickHouse `Geometry` (Variant) 类型。

<div id="allow_experimental_hash_functions">
  ## allow\_experimental\_hash\_functions
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

启用Experimental哈希函数

<div id="allow_experimental_iceberg_compaction">
  ## allow\_experimental\_iceberg\_compaction
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许显式地对 Iceberg 表执行 'OPTIMIZE'。

<div id="allow_experimental_join_right_table_sorting">
  ## allow\_experimental\_join\_right\_table\_sorting
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

如果将其设置为 true，且满足 `join_to_sort_minimum_perkey_rows` 和 `join_to_sort_maximum_table_rows` 的条件，则会按键对右表重新排序，以提升 left 或 inner hash join 的性能。

<div id="allow_experimental_json_lazy_type_hints">
  ## allow\_experimental\_json\_lazy\_type\_hints
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

为 JSON 类型启用Experimental的惰性类型提示。此功能可通过延迟类型提示求值来优化 JSON 类型转换。

<div id="allow_experimental_kafka_offsets_storage_in_keeper">
  ## allow\_experimental\_kafka\_offsets\_storage\_in\_keeper
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许使用一项 Experimental 功能，将 Kafka 相关偏移量存储在 ClickHouse Keeper 中。启用后，可以为 Kafka 表引擎指定 ClickHouse Keeper 路径和副本名称。这样一来，系统将不再使用常规的 Kafka 引擎，而会改用一种新的存储引擎类型，优先将已提交的偏移量存储在 ClickHouse Keeper 中

<div id="allow_experimental_kusto_dialect">
  ## allow\_experimental\_kusto\_dialect
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

启用 Kusto 查询语言 (KQL)，可作为 SQL 的替代方案。

<div id="allow_experimental_materialized_postgresql_table">
  ## allow\_experimental\_materialized\_postgresql\_table
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许使用 MaterializedPostgreSQL 表引擎。默认处于禁用状态，因为该功能仍处于 Experimental 阶段

<div id="allow_experimental_nlp_functions">
  ## allow\_experimental\_nlp\_functions
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

启用 Experimental 自然语言处理函数。

<div id="allow_experimental_nullable_tuple_type">
  ## allow\_experimental\_nullable\_tuple\_type
</div>

<BetaBadge />

**别名**: `enable_nullable_tuple_type`

<SettingsInfoBlock type="Bool" default_value="0" />

允许在表中创建 [Nullable](/zh/reference/data-types/nullable) [Tuple](/zh/reference/data-types/tuple) 列。

此设置不控制提取出的 Tuple 子列是否可以为 `Nullable` (例如，从 Dynamic、Variant、JSON 或 Tuple 列中提取出的子列) 。
请使用 `allow_nullable_tuple_in_extracted_subcolumns` 来控制提取出的 Tuple 子列是否可以为 `Nullable`。

<div id="allow_experimental_object_storage_queue_hive_partitioning">
  ## allow\_experimental\_object\_storage\_queue\_hive\_partitioning
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许在 S3Queue/AzureQueue 引擎中使用 Hive 分区

<div id="allow_experimental_paimon_storage_engine">
  ## allow\_experimental\_paimon\_storage\_engine
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许创建使用 Paimon\* 表引擎的表。

<div id="allow_experimental_parallel_reading_from_replicas">
  ## allow\_experimental\_parallel\_reading\_from\_replicas
</div>

**别名**: `enable_parallel_replicas`

<SettingsInfoBlock type="UInt64" default_value="0" />

对每个分片，SELECT 查询执行时最多可使用 `max_parallel_replicas` 个副本。读取会并行执行，并进行动态协调。0 - 禁用，1 - 启用，失败时静默禁用，2 - 启用，失败时抛出异常

<div id="allow_experimental_polyglot_dialect">
  ## allow\_experimental\_polyglot\_dialect
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

启用 polyglot SQL 转译器：可将 30 多种 SQL 方言 (MySQL、PostgreSQL、SQLite、Snowflake、DuckDB 等) 转译为 ClickHouse SQL。

<div id="allow_experimental_prql_dialect">
  ## allow\_experimental\_prql\_dialect
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

启用 PRQL——作为 SQL 的一种替代方案。

<div id="allow_experimental_time_series_aggregate_functions">
  ## allow\_experimental\_time\_series\_aggregate\_functions
</div>

<ExperimentalBadge />

**别名**: `allow_experimental_ts_to_grid_aggregate_function`

<SettingsInfoBlock type="Bool" default_value="0" />

用于进行类似 Prometheus 的时间序列重采样、rate 和 delta 计算的Experimental timeSeries\* 聚合函数。

<div id="allow_experimental_time_series_table">
  ## allow\_experimental\_time\_series\_table
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许创建使用 [TimeSeries](/zh/reference/engines/table-engines/integrations/time-series) 表引擎的表。可选值：

* 0 — [TimeSeries](/zh/reference/engines/table-engines/integrations/time-series) 表引擎已禁用。
* 1 — [TimeSeries](/zh/reference/engines/table-engines/integrations/time-series) 表引擎已启用。

<div id="allow_experimental_unique_key">
  ## allow\_experimental\_unique\_key
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许在 MergeTree 家族引擎上使用 `UNIQUE KEY` 子句创建表。

<div id="allow_experimental_url_wildcard_from_index_pages">
  ## allow\_experimental\_url\_wildcard\_from\_index\_pages
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

允许 `url()` 和 `ENGINE = URL` 通过 HTTP 索引页进行 Experimental 通配符展开。

<div id="allow_experimental_window_view">
  ## allow\_experimental\_window\_view
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

启用 WINDOW VIEW。该功能尚不成熟。

<div id="allow_experimental_ytsaurus_dictionary_source">
  ## allow\_experimental\_ytsaurus\_dictionary\_source
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

用于与 YTsaurus 集成的 Experimental 字典源。

<div id="allow_experimental_ytsaurus_table_engine">
  ## allow\_experimental\_ytsaurus\_table\_engine
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

用于集成 YTsaurus 的 Experimental 表引擎。

<div id="allow_experimental_ytsaurus_table_function">
  ## allow\_experimental\_ytsaurus\_table\_function
</div>

<ExperimentalBadge />

<SettingsInfoBlock type="Bool" default_value="0" />

用于与 YTsaurus 集成的 Experimental 表引擎。