add v8.5.5 release notes #21195

qiancai · 2025-12-16T08:12:29Z

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As in the title, this PR adds the release note doc for v8.5.5.

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This PR is translated from: add v8.5.5 release notes docs#22190
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releases/release-8.5.5.md

Co-authored-by: zhaoshangzi <[email protected]> Co-authored-by: Frank945946 <[email protected]>

joechenrh

LGTM, for the ADD INDEX part.

ti-chi-bot · 2025-12-23T09:47:11Z

@joechenrh: adding LGTM is restricted to approvers and reviewers in OWNERS files.

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releases/release-8.5.5.md

Co-authored-by: zhaoshangzi <[email protected]>

releases/release-8.5.5.md

lcwangchao · 2025-12-25T02:43:24Z

releases/release-8.5.5.md

+
+* 提示索引下推到TiKV提升查询性能 [#62575](https://github.com/pingcap/tidb/issues/62575) @[lcwangchao](https://github.com/lcwangchao) **tw@qiancai** <!--1899-->
+
+    通过hint INDEX_LOOKUP_PUSHDOWN(t1_name, idx1_name [, idx2_name ...]) 提示优化器将指定索引查询下推到TiKV，减少远程调用的次数，经过测试数据对比显示性能可提升约20%左右，最优可提升到40%。本特性一般建议结合表 affinity 属性使用，即表属性 AFFINITY="table" 或者 分区表属性 AFFINITY="partition" 。


实际数据可能根据环境和负载不同有很大区别，这个数据目前是混合负载的结果，不光包含 pushdown

@zhaoshangzi PTAL

通过hint INDEX_LOOKUP_PUSHDOWN(t1_name, idx1_name [, idx2_name ...]) 提示优化器将指定索引查询下推到TiKV，减少远程调用的次数，性能在理论上有提升，但具体提升比例需要结合业务场景实际测试。本特性一般建议结合表 affinity 属性使用，即表属性 AFFINITY="table" 或者分区表属性 AFFINITY="partition" 。

lhy1024 · 2025-12-25T03:02:09Z

releases/release-8.5.5.md

+
+* 表级和分区级亲和性属性 AFFINITY [#9764](https://github.com/tikv/pd/issues/9764) @[lhy1024](https://github.com/lhy1024) **tw@qiancai** <!--2317-->
+
+    为表或者分区表新增亲和性属性，设置亲和性属性后，PD会将表或分区的Region归为相同的一个亲和性分组中，这些Region的Leader、Voter 会被优先调度到指定TiKV Store上。有AFFNITY属性的表和分区在查询时，由于索引、表数据的Region都在一个TiKV Store上，因此优化器可结合 hint INDEX_LOOKUP_PUSHDOWN 指定将对应索引查询下推，减少跨节点分散查询带来的延迟，根据测试数据对比性能可约提升20%。


这个数据可能会有偏差，根据负载不同

为表或者分区表新增亲和性属性，设置亲和性属性后，PD会将表或分区的Region归为相同的一个亲和性分组中，这些Region的Leader、Voter 会被优先调度到指定TiKV Store上。有AFFNITY属性的表和分区在查询时，由于索引、表数据的Region都在一个TiKV Store上，因此优化器可结合 hint INDEX_LOOKUP_PUSHDOWN 指定将对应索引查询下推，减少跨节点分散查询带来的延迟，提升性能

ti-chi-bot · 2026-01-14T01:18:29Z

@hbisheng: adding LGTM is restricted to approvers and reviewers in OWNERS files.

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ti-chi-bot · 2026-01-14T04:19:01Z

@zhaoshangzi: adding LGTM is restricted to approvers and reviewers in OWNERS files.

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releases/release-8.5.5.md

Co-authored-by: Aolin <[email protected]>

Co-authored-by: Bisheng Huang <[email protected]>

releases/release-8.5.5.md

ti-chi-bot · 2026-01-14T10:22:51Z

[LGTM Timeline notifier]

Timeline:

2026-01-14 01:40:49.833859257 +0000 UTC m=+408093.895724191: ☑️ agreed by hfxsd.
2026-01-14 10:22:49.981956587 +0000 UTC m=+439414.043821496: ☑️ agreed by Oreoxmt.

qiancai · 2026-01-15T09:12:41Z

/approve

ti-chi-bot · 2026-01-15T09:12:49Z

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qiancai

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ti-chi-bot · 2026-01-15T09:16:07Z

In response to a cherrypick label: new pull request created to branch release-8.5: #21281.

Co-authored-by: zhaoshangzi <[email protected]> Co-authored-by: Frank945946 <[email protected]> Co-authored-by: JaySon <[email protected]> Co-authored-by: hongyunyan <[email protected]> Co-authored-by: Ryan Leung <[email protected]> Co-authored-by: Liqi Geng <[email protected]> Co-authored-by: you06 <[email protected]> Co-authored-by: Ruihao Chen <[email protected]> Co-authored-by: Grace Cai <[email protected]> Co-authored-by: Aolin <[email protected]> Co-authored-by: Bisheng Huang <[email protected]> Co-authored-by: Lilian Lee <[email protected]> Co-authored-by: Aolin <[email protected]> Co-authored-by: xixirangrang <[email protected]> Co-authored-by: Weizhen Wang <[email protected]> Co-authored-by: tongjian <[email protected]>

Add temp.md

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qiancai added do-not-merge/work-in-progress Indicates that a PR should not merge because it is a work in progress. needs-cherry-pick-release-8.5 Should cherry pick this PR to release-8.5 branch. translation/from-docs This PR is translated from a PR in pingcap/docs. labels Dec 16, 2025

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Create release-8.5.5.md

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qiancai self-assigned this Dec 16, 2025

qiancai added 2 commits December 17, 2025 14:12

add feature description for #56522 and #58685

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add pingcap#17221

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Add three features

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Co-authored-by: zhaoshangzi <[email protected]> Co-authored-by: Frank945946 <[email protected]>

joechenrh approved these changes Dec 23, 2025

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add more features according to English PR

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qiancai commented Dec 24, 2025

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qiancai commented Dec 24, 2025

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add improvements and bug fixes

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qiancai and others added 2 commits December 25, 2025 09:55

add two new features

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Co-authored-by: zhaoshangzi <[email protected]>

adjust the feature order and add two features

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add the issue information for a feature

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Update releases/release-8.5.5.md

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qiancai and others added 5 commits January 14, 2026 17:02

remove a duplicated #58985 for the same issue

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fix a format issue

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Co-authored-by: Aolin <[email protected]>

Update releases/release-8.5.5.md

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Co-authored-by: Bisheng Huang <[email protected]>

fix format issues

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fix format issues

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update the release date

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qiancai changed the title ~~[WIP]: add v8.5.5 release notes~~ add v8.5.5 release notes Jan 15, 2026

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qiancai merged commit 86c5491 into pingcap:master Jan 15, 2026
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qiancai deleted the add-8.5.5-rn-22190 branch January 15, 2026 09:15

ti-chi-bot mentioned this pull request Jan 15, 2026

add v8.5.5 release notes (#21195) #21281

Merged

13 tasks


		* 提示索引下推到TiKV提升查询性能 [#62575](https://github.com/pingcap/tidb/issues/62575) @[lcwangchao](https://github.com/lcwangchao) tw@qiancai <!--1899-->

		通过hint INDEX_LOOKUP_PUSHDOWN(t1_name, idx1_name [, idx2_name ...]) 提示优化器将指定索引查询下推到TiKV，减少远程调用的次数，经过测试数据对比显示性能可提升约20%左右，最优可提升到40%。本特性一般建议结合表 affinity 属性使用，即表属性 AFFINITY="table" 或者分区表属性 AFFINITY="partition" 。


		* 表级和分区级亲和性属性 AFFINITY [#9764](https://github.com/tikv/pd/issues/9764) @[lhy1024](https://github.com/lhy1024) tw@qiancai <!--2317-->

		为表或者分区表新增亲和性属性，设置亲和性属性后，PD会将表或分区的Region归为相同的一个亲和性分组中，这些Region的Leader、Voter 会被优先调度到指定TiKV Store上。有AFFNITY属性的表和分区在查询时，由于索引、表数据的Region都在一个TiKV Store上，因此优化器可结合 hint INDEX_LOOKUP_PUSHDOWN 指定将对应索引查询下推，减少跨节点分散查询带来的延迟，根据测试数据对比性能可约提升20%。

add v8.5.5 release notes #21195

add v8.5.5 release notes #21195

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qiancai commented Dec 16, 2025

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[LGTM Timeline notifier]

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