> ## 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.

# stream_* 会话设置

> stream_* 生成分组中的 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 [源代码](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp) 自动生成。

<div id="stream_flush_interval_ms">
  ## stream\_flush\_interval\_ms
</div>

<SettingsInfoBlock type="毫秒" default_value="7500" />

适用于流式的表：当发生超时，或某个线程生成了 [max\_insert\_block\_size](/docs/zh/reference/settings/session-settings/max-insert#max_insert_block_size) 行时生效。

默认值为 7500。

该值越小，数据刷写到表中的频率越高。将该值设置得过低会导致性能下降。

<div id="stream_poll_timeout_ms">
  ## stream\_poll\_timeout\_ms
</div>

<SettingsInfoBlock type="毫秒" default_value="500" />

从流式存储读取或向其写入数据时，轮询操作的超时时间。