> ## Documentation Index
> Fetch the complete documentation index at: https://clickhouse.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# storage_* 会话设置

> storage_* 生成组中的 ClickHouse 会话设置。

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](/docs/zh/reference/system-tables/settings) 中查看，且由 [源文件](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp) 自动生成。

<div id="storage_file_read_method">
  ## storage\_file\_read\_method
</div>

<SettingsInfoBlock type="LocalFSReadMethod" default_value="pread" />

从存储文件读取数据的方法，可选值包括：`read`、`pread`、`mmap`。`mmap` 方法不适用于 clickhouse-server (它是为 clickhouse-local 设计的) 。

<div id="storage_system_stack_trace_pipe_read_timeout_ms">
  ## storage\_system\_stack\_trace\_pipe\_read\_timeout\_ms
</div>

<SettingsInfoBlock type="毫秒" default_value="100" />

查询 `system.stack_trace` 表时，从管道中读取线程信息的最长时间。此设置仅用于测试，用户不应修改。