system-variables: add tidb_paging_size_bytes (internal use) #21752
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@@ -4745,6 +4745,18 @@ SHOW WARNINGS; | |||||
| - 范围：`[0, 2147483647]` | ||||||
| - 控制优化器估算逻辑的更迭。更改该变量值后，优化器的估算逻辑会产生较大的改变。目前该变量的有效值只有 `0`，不建议设为其它值。 | ||||||
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| ### `tidb_paging_size_bytes` <span class="version-mark">从 v9.0.0 版本开始引入</span> | ||||||
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| - 作用域：SESSION | GLOBAL | ||||||
| - 是否持久化到集群：是 | ||||||
| - 是否受 Hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value) 控制：是 | ||||||
| - 类型：整数型 | ||||||
| - 默认值：`0` | ||||||
| - 范围：`[0, 9223372036854775807]` | ||||||
| - 单位：字节 | ||||||
| - 这个变量用来设置 coprocessor 协议中单个 paging 响应的字节数上限，用于在按行数分页（[`tidb_max_paging_size`](#tidb_max_paging_size-从-v630-版本开始引入)）之外，额外提供按字节分页的能力。默认值为 `0`，表示关闭按字节分页。该功能仅在开启[资源管控](/tidb-resource-control-ru-groups.md)时生效，供 PD 资源管控做 RU 预扣费使用。 | ||||||
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There was a problem hiding this comment. reason: “预扣费”通常表示预先扣除费用，容易使人误以为 RU 是货币费用；此处实际是预扣 RU。
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There was a problem hiding this comment. 已采纳该措辞，并同步了 pingcap/tidb#69868 的改动：默认值更新为 |
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| - 该变量是 TiDB 内部使用的变量，**不推荐**修改该变量的值。 | ||||||
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| ### `tidb_partition_prune_mode` <span class="version-mark">从 v5.1 版本开始引入</span> | ||||||
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| > **警告：** | ||||||
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🎯 Functional Correctness | 🟡 Minor | ⚡ Quick win
将变量类型标注为无符号整数型。
PR 目标明确该变量为 unsigned，但当前文档写成“整数型”，容易让读者误以为支持负值；这也与
[0, 9223372036854775807]的范围不一致。