> ## 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.

# optimize_move_to_prewhere_* 会话设置

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

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，并由 [源代码](https://github.com/ClickHouse/ClickHouse/blob/master/src/Core/Settings.cpp) 自动生成。

<div id="optimize_move_to_prewhere">
  ## optimize\_move\_to\_prewhere
</div>

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

启用或禁用 [SELECT](/docs/zh/reference/statements/select/index) 查询中的自动 [PREWHERE](/docs/zh/reference/statements/select/prewhere) 优化。

仅对 [\*MergeTree](/docs/zh/reference/engines/table-engines/mergetree-family/index) 表生效。

可能的值：

* 0 — 禁用自动 `PREWHERE` 优化。
* 1 — 启用自动 `PREWHERE` 优化。

<div id="optimize_move_to_prewhere_if_final">
  ## optimize\_move\_to\_prewhere\_if\_final
</div>

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

启用或禁用在带有 [FINAL](/docs/zh/reference/statements/select/from#final-modifier) 修饰符的 [SELECT](/docs/zh/reference/statements/select/index) 查询中自动应用 [PREWHERE](/docs/zh/reference/statements/select/prewhere) 优化。

仅适用于 [\*MergeTree](/docs/zh/reference/engines/table-engines/mergetree-family/index) 表。

可能的值：

* 0 — 禁用在带有 `FINAL` 修饰符的 `SELECT` 查询中自动应用 `PREWHERE` 优化。
* 1 — 启用在带有 `FINAL` 修饰符的 `SELECT` 查询中自动应用 `PREWHERE` 优化。

**另请参见**

* [optimize\_move\_to\_prewhere](/docs/zh/reference/settings/session-settings/optimize-move-to-prewhere#optimize_move_to_prewhere) 设置