> ## 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.

# database_replicated_* 会话设置

> ClickHouse 在 database_replicated_* 自动生成分组中的会话设置。

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>;
};

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

<div id="database_replicated_allow_explicit_uuid">
  ## database\_replicated\_allow\_explicit\_uuid
</div>

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

0 - 不允许在 Replicated 数据库中显式指定表 UUID。1 - 允许。2 - 允许，但会忽略指定的 UUID，改为生成一个随机 UUID。

<div id="database_replicated_allow_heavy_create">
  ## database\_replicated\_allow\_heavy\_create
</div>

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

允许在 Replicated 数据库引擎中执行长时间运行的 DDL 查询 (CREATE AS SELECT 和 POPULATE) 。请注意，这可能会长时间阻塞 DDL 队列。

<div id="database_replicated_allow_only_replicated_engine">
  ## database\_replicated\_allow\_only\_replicated\_engine
</div>

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

仅允许在使用 Replicated 引擎的数据库中创建复制表。

Cloud 默认值：`1`。

<div id="database_replicated_allow_replicated_engine_arguments">
  ## database\_replicated\_allow\_replicated\_engine\_arguments
</div>

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

0 - 不允许在 Replicated 数据库中的 \*MergeTree 表上显式指定 ZooKeeper 路径和副本名称。1 - 允许。2 - 允许，但会忽略指定的路径，改用默认路径。3 - 允许且不记录警告。

<div id="database_replicated_always_detach_permanently">
  ## database\_replicated\_always\_detach\_permanently
</div>

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

如果数据库引擎为 Replicated，则以 DETACH TABLE PERMANENTLY 的方式执行 DETACH TABLE

<div id="database_replicated_enforce_synchronous_settings">
  ## database\_replicated\_enforce\_synchronous\_settings
</div>

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

强制某些查询以同步方式等待 (另请参见 database\_atomic\_wait\_for\_drop\_and\_detach\_synchronously、mutations\_sync、alter\_sync) 。不建议启用这些设置。

<div id="database_replicated_initial_query_timeout_sec">
  ## database\_replicated\_initial\_query\_timeout\_sec
</div>

<SettingsInfoBlock type="UInt64" default_value="300" />

设置初始 DDL 查询等待 Replicated 数据库 处理之前 DDL 队列 条目的时长 (以秒为单位) 。

Possible values:

* 正整数。
* 0 — 无限制。