> ## 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.

# shared_merge_* MergeTree 表设置

> ClickHouse 在 shared_merge_* 自动生成组中的 MergeTree 表设置。

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.merge\_tree\_settings](/docs/zh/reference/system-tables/merge_tree_settings) 中查看，且由 ClickHouse 源代码自动生成。

<div id="shared_merge_tree_activate_coordinated_merges_tasks">
  ## shared\_merge\_tree\_activate\_coordinated\_merges\_tasks
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.9"},{"label": "0"},{"label": "新设置"}]}, {"id": "row-2","items": [{"label": "25.8"},{"label": "0"},{"label": "新设置"}]}, {"id": "row-3","items": [{"label": "25.7"},{"label": "0"},{"label": "新设置"}]}, {"id": "row-4","items": [{"label": "25.6"},{"label": "0"},{"label": "新设置"}]}, {"id": "row-5","items": [{"label": "25.10"},{"label": "0"},{"label": "新设置"}]}]} />

启用协调式合并任务的重新调度。即使在
shared\_merge\_tree\_enable\_coordinated\_merges=0 时，它也可能很有用，因为这会补充 merge coordinator
统计信息，并有助于冷启动。

<div id="shared_merge_tree_create_per_replica_metadata_nodes">
  ## shared\_merge\_tree\_create\_per\_replica\_metadata\_nodes
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.11"},{"label": "0"},{"label": "减少 Keeper 中的元数据量。"}]}, {"id": "row-2","items": [{"label": "25.1"},{"label": "1"},{"label": "Cloud sync"}]}]} />

启用在 ZooKeeper 中为每个副本创建各自的 /metadata 和 /columns 节点。
仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_disable_merges_and_mutations_assignment">
  ## shared\_merge\_tree\_disable\_merges\_and\_mutations\_assignment
</div>

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

停止 shared merge tree 的合并任务分配。仅在 ClickHouse
Cloud
中可用

<div id="shared_merge_tree_empty_partition_lifetime">
  ## shared\_merge\_tree\_empty\_partition\_lifetime
</div>

<SettingsInfoBlock type="秒" default_value="86400" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.9"},{"label": "86400"},{"label": "新设置"}]}]} />

当分区没有 parts 时，会在 Keeper 中保留多少秒。

<div id="shared_merge_tree_enable_automatic_empty_partitions_cleanup">
  ## shared\_merge\_tree\_enable\_automatic\_empty\_partitions\_cleanup
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.2"},{"label": "1"},{"label": "默认启用"}]}, {"id": "row-2","items": [{"label": "25.9"},{"label": "0"},{"label": "新设置"}]}]} />

启用自动清理空分区的 Keeper 条目。

<div id="shared_merge_tree_enable_coordinated_merges">
  ## shared\_merge\_tree\_enable\_coordinated\_merges
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.6"},{"label": "1"},{"label": "默认启用协调合并策略"}]}, {"id": "row-2","items": [{"label": "25.5"},{"label": "0"},{"label": "新设置"}]}]} />

启用协调合并策略

<div id="shared_merge_tree_enable_keeper_parts_extra_data">
  ## shared\_merge\_tree\_enable\_keeper\_parts\_extra\_data
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.6"},{"label": "1"},{"label": "默认启用协调合并"}]}, {"id": "row-2","items": [{"label": "25.3"},{"label": "0"},{"label": "新设置"}]}]} />

启用向 virtual parts 写入属性，并在 Keeper 中提交块

<div id="shared_merge_tree_enable_outdated_parts_check">
  ## shared\_merge\_tree\_enable\_outdated\_parts\_check
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "1"},{"label": "Cloud sync"}]}]} />

启用对过期分区片段的检查。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_idle_parts_update_seconds">
  ## shared\_merge\_tree\_idle\_parts\_update\_seconds
</div>

<SettingsInfoBlock type="UInt64" default_value="3600" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "3600"},{"label": "Cloud sync"}]}]} />

在 shared merge tree 中，未由 ZooKeeper
watch 触发时更新 parts 的时间间隔 (秒) 。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_inactive_replica_cutoff_seconds">
  ## shared\_merge\_tree\_inactive\_replica\_cutoff\_seconds
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.6"},{"label": "0"},{"label": "用于控制后台清理在多长时间内仍将非活动副本纳入考虑范围的新增设置（0 表示两个 ZooKeeper 会话超时）"}]}]} />

后台清理
(`OutdatedPartsQuorumThread`) 在多长时间内仍会将非活动副本纳入考虑：当某个副本处于非活动状态的时间少于该秒数时，
它仍会阻止移除过期分区片段以及截断已完成的变更。值为 0
表示使用默认值，即两个 ZooKeeper 会话超时。
仅适用于 ClickHouse Cloud

<div id="shared_merge_tree_initial_parts_update_backoff_ms">
  ## shared\_merge\_tree\_initial\_parts\_update\_backoff\_ms
</div>

<SettingsInfoBlock type="UInt64" default_value="50" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.2"},{"label": "50"},{"label": "新设置"}]}]} />

parts 更新的初始退避时间。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_interserver_http_connection_timeout_ms">
  ## shared\_merge\_tree\_interserver\_http\_connection\_timeout\_ms
</div>

<SettingsInfoBlock type="UInt64" default_value="100" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.2"},{"label": "100"},{"label": "新设置"}]}]} />

服务器间 HTTP 连接超时。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_interserver_http_timeout_ms">
  ## shared\_merge\_tree\_interserver\_http\_timeout\_ms
</div>

<SettingsInfoBlock type="UInt64" default_value="10000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "10000"},{"label": "Cloud sync"}]}]} />

interserver HTTP 通信的超时时间。仅在 ClickHouse
Cloud
中可用

<div id="shared_merge_tree_leader_update_period_random_add_seconds">
  ## shared\_merge\_tree\_leader\_update\_period\_random\_add\_seconds
</div>

<SettingsInfoBlock type="UInt64" default_value="10" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "10"},{"label": "Cloud sync"}]}]} />

为避免惊群效应，向
shared\_merge\_tree\_leader\_update\_period 添加一个从 0 到 x 秒均匀分布的随机值。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_leader_update_period_seconds">
  ## shared\_merge\_tree\_leader\_update\_period\_seconds
</div>

<SettingsInfoBlock type="UInt64" default_value="30" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "30"},{"label": "Cloud sync"}]}]} />

重新检查 parts 更新 leader 的最长周期。仅在
ClickHouse Cloud
中可用

<div id="shared_merge_tree_max_outdated_parts_to_process_at_once">
  ## shared\_merge\_tree\_max\_outdated\_parts\_to\_process\_at\_once
</div>

<SettingsInfoBlock type="UInt64" default_value="1000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "1000"},{"label": "Cloud sync"}]}]} />

在一次 HTTP 请求中，leader 尝试确认可移除的过期分区片段的最大数量。
仅在 ClickHouse Cloud 中可用。

<div id="shared_merge_tree_max_parts_update_backoff_ms">
  ## shared\_merge\_tree\_max\_parts\_update\_backoff\_ms
</div>

<SettingsInfoBlock type="UInt64" default_value="5000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.2"},{"label": "5000"},{"label": "新设置"}]}]} />

parts 更新的最大退避时间。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_max_parts_update_leaders_in_total">
  ## shared\_merge\_tree\_max\_parts\_update\_leaders\_in\_total
</div>

<SettingsInfoBlock type="UInt64" default_value="6" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "6"},{"label": "Cloud sync"}]}]} />

parts update leaders 的最大数量上限。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_max_parts_update_leaders_per_az">
  ## shared\_merge\_tree\_max\_parts\_update\_leaders\_per\_az
</div>

<SettingsInfoBlock type="UInt64" default_value="2" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "2"},{"label": "Cloud sync"}]}]} />

parts update leader 的最大数量。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_max_replicas_for_parts_deletion">
  ## shared\_merge\_tree\_max\_replicas\_for\_parts\_deletion
</div>

<SettingsInfoBlock type="UInt64" default_value="10" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "10"},{"label": "Cloud sync"}]}]} />

参与 parts 删除 (killer 线程) 的最大副本数上限。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_max_replicas_to_merge_parts_for_each_parts_range">
  ## shared\_merge\_tree\_max\_replicas\_to\_merge\_parts\_for\_each\_parts\_range
</div>

<SettingsInfoBlock type="UInt64" default_value="5" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "5"},{"label": "Cloud sync"}]}]} />

尝试为可能发生冲突的合并进行分配的最大副本数 (可
避免在合并分配中出现冗余冲突) 。0 表示禁用。仅
在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_max_suspicious_broken_parts">
  ## shared\_merge\_tree\_max\_suspicious\_broken\_parts
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.2"},{"label": "0"},{"label": "SMT 的损坏 parts 最大数量；超过该数量时，将禁止自动分离"}]}]} />

SMT 的损坏 parts 最大数量；超过该数量时，将禁止自动分离。

<div id="shared_merge_tree_max_suspicious_broken_parts_bytes">
  ## shared\_merge\_tree\_max\_suspicious\_broken\_parts\_bytes
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.2"},{"label": "0"},{"label": "SMT 中所有损坏 parts 的最大总大小；如果超过该值，则禁止自动 detach"}]}]} />

SMT 中所有损坏 parts 的最大总大小；如果超过该值，则禁止自动 detach。

<div id="shared_merge_tree_memo_ids_remove_timeout_seconds">
  ## shared\_merge\_tree\_memo\_ids\_remove\_timeout\_seconds
</div>

<SettingsInfoBlock type="Int64" default_value="1800" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "1800"},{"label": "Cloud sync"}]}]} />

我们会将插入记忆化 ID 保留多长时间，以避免在插入重试期间发生错误操作。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_merge_coordinator_distribution_algorithm">
  ## shared\_merge\_tree\_merge\_coordinator\_distribution\_algorithm
</div>

<SettingsInfoBlock type="MergeCoordinatorDistributionAlgorithm" default_value="water_filling" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.7"},{"label": "water_filling"},{"label": "新增设置，用于控制 merge coordinator 在副本之间分发 merge 操作时所使用的算法"}]}]} />

merge coordinator 线程在副本之间分发 merge 操作时使用的算法

<div id="shared_merge_tree_merge_coordinator_election_check_period_ms">
  ## shared\_merge\_tree\_merge\_coordinator\_election\_check\_period\_ms
</div>

<SettingsInfoBlock type="毫秒" default_value="30000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.5"},{"label": "30000"},{"label": "新设置"}]}]} />

merge coordinator 选举线程的运行间隔时间

<div id="shared_merge_tree_merge_coordinator_factor">
  ## shared\_merge\_tree\_merge\_coordinator\_factor
</div>

<SettingsInfoBlock type="Float" default_value="1.1" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.5"},{"label": "1.100000023841858"},{"label": "新设置"}]}, {"id": "row-2","items": [{"label": "25.10"},{"label": "1.100000023841858"},{"label": "负载后降低协调器休眠时间"}]}]} />

协调器线程延迟时间的变化系数

<div id="shared_merge_tree_merge_coordinator_fetch_fresh_metadata_period_ms">
  ## shared\_merge\_tree\_merge\_coordinator\_fetch\_fresh\_metadata\_period\_ms
</div>

<SettingsInfoBlock type="毫秒" default_value="10000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.5"},{"label": "10000"},{"label": "新设置"}]}]} />

合并协调器应隔多久与 ZooKeeper 同步一次，以获取最新元数据

<div id="shared_merge_tree_merge_coordinator_max_merge_request_size">
  ## shared\_merge\_tree\_merge\_coordinator\_max\_merge\_request\_size
</div>

<SettingsInfoBlock type="UInt64" default_value="20" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.5"},{"label": "20"},{"label": "新设置"}]}]} />

协调器一次可向 MergerMutator 请求的合并数量

<div id="shared_merge_tree_merge_coordinator_max_period_ms">
  ## shared\_merge\_tree\_merge\_coordinator\_max\_period\_ms
</div>

<SettingsInfoBlock type="毫秒" default_value="10000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.5"},{"label": "新设置"},{"label": "10000"}]}]} />

merge coordinator 线程两次运行之间的最大时间间隔

<div id="shared_merge_tree_merge_coordinator_merges_prepare_count">
  ## shared\_merge\_tree\_merge\_coordinator\_merges\_prepare\_count
</div>

<SettingsInfoBlock type="UInt64Auto" default_value="auto" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.4"},{"label": "auto"},{"label": "将该设置设为 auto：每个副本的最大 merge 任务数 * 活跃副本数"}]}, {"id": "row-2","items": [{"label": "25.5"},{"label": "100"},{"label": "新设置"}]}]} />

coordinator 应准备并分发给工作线程的 merge 条目数量。
当设置为 `auto` 时，其值等于单个副本允许的最大 merge 任务数乘以活跃副本数。

<div id="shared_merge_tree_merge_coordinator_min_period_ms">
  ## shared\_merge\_tree\_merge\_coordinator\_min\_period\_ms
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.5"},{"label": "1"},{"label": "新设置"}]}]} />

merge coordinator 线程两次运行之间的最短间隔时间

<div id="shared_merge_tree_merge_worker_fast_timeout_ms">
  ## shared\_merge\_tree\_merge\_worker\_fast\_timeout\_ms
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.5"},{"label": "100"},{"label": "新设置"}]}]} />

合并工作线程在即时操作后需要更新其状态时使用的超时时间

<div id="shared_merge_tree_merge_worker_regular_timeout_ms">
  ## shared\_merge\_tree\_merge\_worker\_regular\_timeout\_ms
</div>

<SettingsInfoBlock type="毫秒" default_value="10000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.5"},{"label": "10000"},{"label": "新设置"}]}]} />

合并工作线程两次运行之间的间隔时间

<div id="shared_merge_tree_outdated_parts_group_size">
  ## shared\_merge\_tree\_outdated\_parts\_group\_size
</div>

<SettingsInfoBlock type="UInt64" default_value="2" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.9"},{"label": "2"},{"label": "新设置"}]}]} />

将有多少个副本位于同一个 rendezvous 哈希组中，以进行过期分区片段清理。
仅在 ClickHouse Cloud 中可用。

<div id="shared_merge_tree_partitions_hint_ratio_to_reload_merge_pred_for_mutations">
  ## shared\_merge\_tree\_partitions\_hint\_ratio\_to\_reload\_merge\_pred\_for\_mutations
</div>

<SettingsInfoBlock type="Float" default_value="0.5" />

当 `<candidate
partitions for mutations only (partitions that cannot be merged)>/<candidate
partitions for mutations>` 的比率高于此设置值时，会在 merge/mutate 选择任务中重新加载合并谓词。仅在
ClickHouse Cloud 中可用

<div id="shared_merge_tree_parts_load_batch_size">
  ## shared\_merge\_tree\_parts\_load\_batch\_size
</div>

<SettingsInfoBlock type="UInt64" default_value="32" />

一次可调度的拉取 parts 元数据作业数量。仅在
ClickHouse Cloud
中可用

<div id="shared_merge_tree_postpone_next_merge_for_locally_merged_parts_ms">
  ## shared\_merge\_tree\_postpone\_next\_merge\_for\_locally\_merged\_parts\_ms
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "0"},{"label": "Cloud sync"}]}]} />

在不启动包含该分片的新合并的情况下，保留本地已合并分片的时长。
这样可让其他副本有机会拉取该分片并启动此次合并。
仅在 ClickHouse Cloud 中可用。

<div id="shared_merge_tree_postpone_next_merge_for_locally_merged_parts_rows_threshold">
  ## shared\_merge\_tree\_postpone\_next\_merge\_for\_locally\_merged\_parts\_rows\_threshold
</div>

<SettingsInfoBlock type="UInt64" default_value="1000000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "1000000"},{"label": "Cloud sync"}]}]} />

刚在本地完成合并后，用于推迟为其分配下一次合并的 分片 最小大小 (按行数计算) 。仅在 ClickHouse Cloud 中可用。

<div id="shared_merge_tree_range_for_merge_window_size">
  ## shared\_merge\_tree\_range\_for\_merge\_window\_size
</div>

<SettingsInfoBlock type="UInt64" default_value="10" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "10"},{"label": "Cloud sync"}]}]} />

用于在各副本之间分发 merge 任务的窗口大小 (按块编号计算) 。
同一窗口内的 parts 会分配给相同的副本。
仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_read_virtual_parts_from_leader">
  ## shared\_merge\_tree\_read\_virtual\_parts\_from\_leader
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "1"},{"label": "Cloud sync"}]}]} />

如果可能，则从 leader 读取 virtual parts。仅在 ClickHouse
Cloud
中可用

<div id="shared_merge_tree_replica_set_max_lifetime_seconds">
  ## shared\_merge\_tree\_replica\_set\_max\_lifetime\_seconds
</div>

<SettingsInfoBlock type="秒" default_value="1800" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.4"},{"label": "1800"},{"label": "将默认的副本集后台更新间隔增加到 30 分钟"}]}, {"id": "row-2","items": [{"label": "26.2"},{"label": "300"},{"label": "新设置"}]}]} />

副本在后台尝试更新副本集的频率。下一次运行会在 \[0, value] 秒范围内
按均匀分布引入抖动。例外情况：value = 0 不遵循该规则；
实现中会应用最小 200 毫秒，因此下一次运行会在 \[0, 200] 毫秒范围内引入抖动。

<div id="shared_merge_tree_try_fetch_part_in_memory_data_from_replicas">
  ## shared\_merge\_tree\_try\_fetch\_part\_in\_memory\_data\_from\_replicas
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "0"},{"label": "用于从其他副本拉取 分片 内存数据的新设置"}]}]} />

如果启用，所有副本都会尝试从其他已具有这些数据的副本拉取 分片 的内存数据 (如主键、分区信息等) 。

<div id="shared_merge_tree_try_fetch_part_in_memory_data_from_replicas_on_startup">
  ## shared\_merge\_tree\_try\_fetch\_part\_in\_memory\_data\_from\_replicas\_on\_startup
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.6"},{"label": "0"},{"label": "新增设置，允许 SMT 在启动时从副本而非 S3 下载 分片 数据"}]}]} />

如果启用，所有副本都会在启动时尝试从其他已存在这些数据的副本拉取 分片 的内存数据 (如主键、分区信息等) 。

<div id="shared_merge_tree_update_replica_flags_delay_ms">
  ## shared\_merge\_tree\_update\_replica\_flags\_delay\_ms
</div>

<SettingsInfoBlock type="毫秒" default_value="30000" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.8"},{"label": "30000"},{"label": "新设置"}]}]} />

副本按后台调度尝试重新加载其标志的频率。

<div id="shared_merge_tree_use_metadata_hints_cache">
  ## shared\_merge\_tree\_use\_metadata\_hints\_cache
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "1"},{"label": "Cloud sync"}]}]} />

启用从其他副本上的内存缓存中请求 FS 缓存提示。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_use_outdated_parts_compact_format">
  ## shared\_merge\_tree\_use\_outdated\_parts\_compact\_format
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.9"},{"label": "1"},{"label": "默认启用过期分区片段 v3"}]}, {"id": "row-2","items": [{"label": "25.1"},{"label": "0"},{"label": "Cloud sync"}]}]} />

对过期分区片段使用紧凑格式：可降低 Keeper 负载，并提升
过期分区片段的处理效率。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_use_too_many_parts_count_from_virtual_parts">
  ## shared\_merge\_tree\_use\_too\_many\_parts\_count\_from\_virtual\_parts
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.1"},{"label": "0"},{"label": "Cloud sync"}]}]} />

如果启用，parts 过多计数器将依赖 Keeper 中的共享数据，而不是
本地副本状态。仅在 ClickHouse Cloud 中可用

<div id="shared_merge_tree_use_zookeeper_connection_pool">
  ## shared\_merge\_tree\_use\_zookeeper\_connection\_pool
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.3"},{"label": "0"},{"label": "新设置"}]}]} />

如果启用，SharedMergeTree 将使用服务器级 ZooKeeper 会话池中的一个会话。

<div id="shared_merge_tree_virtual_parts_discovery_batch">
  ## shared\_merge\_tree\_virtual\_parts\_discovery\_batch
</div>

<SettingsInfoBlock type="UInt64" default_value="1" />

<VersionHistory rows={[{"id": "row-1","items": [{"label": "25.8"},{"label": "1"},{"label": "新设置"}]}]} />

应将多少个分区发现操作打包为一个批次

<div id="shared_merge_tree_virtual_parts_partition_atomic_discovery">
  ## shared\_merge\_tree\_virtual\_parts\_partition\_atomic\_discovery
</div>

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

<VersionHistory rows={[{"id": "row-1","items": [{"label": "26.7"},{"label": "1"},{"label": "新设置"}]}]} />

SMT 是否会以原子方式发现 virtual parts 分区，并进行额外的数据拉取和 watch 设置。