i18n(ja): use one rendering for compaction in the reference docs (part 1)

[yahonda]

What is changed, added or deleted? (Required)

Renders "compaction" (RocksDB/TiKV/TiFlash compaction) as コンパクション instead of 圧縮 in the reference docs. 圧縮 is the established Japanese word for "compression", so using it for compaction made sentences like 「圧縮方法」 (EN "Compaction method") or 「保留中の圧縮バイト」 (EN "pending compaction bytes") read as if they were about data compression. コンパクション is already used in the JA docs, for example in コンパクションフィルター.

This is part 1 (29 files, non-release docs). The release notes will follow in a separate PR after the open release-note PRs are merged. storage-engine/ is not included because #24142 already covers it.

How each site was chosen

• Each 圧縮 site was decided from its EN text, not from the Japanese word form.
• Files whose EN uses only "compress/compression" were skipped.
• For the remaining files, each 圧縮 line was matched with its EN line. If the EN line says compaction/compact/compacted, the site was changed; if it says compress/compression, it was kept.
• Lines that could not be matched automatically were checked by hand.

Kept as 圧縮 because EN says "compress":

• dm/dm-replication-logic.md: "compress multiple changes into one change".
• faq/manage-cluster-faq.md: "compressed by TiKV".
• storage-engine/ lines: not touched.
• tidb-lightning/monitor-tidb-lightning.md: 非圧縮 ("uncompressed").
• troubleshoot-high-disk-io.md: 圧縮率の高い圧縮アルゴリズム ("compression algorithm").
• tikv-configuration-file.md (max-bytes-for-level-base): this line mixes both meanings. Only 「不要な圧縮」 and 「L0 の圧縮のトリガー条件」 (compaction) were changed; 「圧縮方法」, 「圧縮されず」, 「圧縮を採用」, and 「圧縮された SST」 (compression) were kept.

Configuration names and code are unchanged.

Which TiDB version(s) do your changes apply to? (Required)

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By default, CHOOSE MASTER ONLY so your changes will be applied to the next TiDB major or minor releases. If your PR involves a product feature behavior change or a compatibility change, CHOOSE THE AFFECTED RELEASE BRANCH(ES) AND MASTER.

For details, see tips for choosing the affected versions.

• i18n-ja-release-8.5 (TiDB Japanese documentation for TiDB 8.5 versions)

What is the related PR or file link(s)?

• This PR is translated from:
• Other reference link(s): i18n(ja): fix translation defects in clinic, sync-diff-inspector, storage-engine, and schema docs #24142

AI agent involvement

• The changes in this PR were primarily made by an AI agent on behalf of the PR author.

Do your changes match any of the following descriptions?

• Delete files
• Change aliases
• Need modification after applied to another branch
• Might cause conflicts after applied to another branch

🤖 Generated with Claude Code

Summary by CodeRabbit

• Documentation
  • Standardized Japanese terminology for compaction across TiKV, TiFlash, RocksDB, and related configuration, operations, monitoring, troubleshooting, and performance guides.
  • Clarified the TI_TELEMETRY_EXTRA size limit and selected configuration descriptions, including flow-control thresholds and backup backend selection. Documented settings and behavior are otherwise unchanged.

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• tikv-configuration-file.md

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📝 Walkthrough

Walkthrough

The documentation updates compaction terminology across TiKV, TiFlash, and related topics. The TiKV configuration guide also adds gc.auto-compaction details and clarifies flow-control threshold overrides.

Changes

Compaction terminology

Layer / File(s)	Summary
TiKV settings and control dynamic-config.md, garbage-collection-configuration.md, pd-configuration-file.md, tikv-configuration-file.md, tikv-control.md	TiKV configuration and control descriptions use compaction terminology. The configuration guide adds gc.auto-compaction details and clarifies flow-control threshold overrides.
Operations and performance guidance best-practices/*, faq/manage-cluster-faq.md, performance-tuning-methods.md, tidb-performance-tuning-config.md, tidb-troubleshooting-map.md, troubleshoot-high-disk-io.md, tune-tikv-thread-performance.md, tidb-lightning/data-import-best-practices.md	Best-practice, performance, and troubleshooting descriptions use compaction terminology. Recommendations and parameter values remain unchanged.
SQL, backup, and import operations br/br-compact-log-backup.md, sql-statements/sql-statement-alter-table-compact.md, tidb-lightning/*	Log backup, SQL compaction, and TiDB Lightning documentation uses compaction terminology. Command examples and documented operation conditions remain unchanged.
Monitoring and related references ai/ti/reference/ti-configuration-and-credentials.md, dashboard/dashboard-monitoring.md, encryption-at-rest.md, faq/sql-faq.md, grafana-tikv-dashboard.md, tiflash/*, tiflash-upgrade-guide.md	Monitoring, encryption, FAQ, telemetry, and TiFlash descriptions use compaction terminology. The TI_TELEMETRY_EXTRA size description specifies a 2 KiB maximum after JSON compaction.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~12 minutes

Change: Other

Suggested reviewers: qiancai

Merge Risk: ⚪ Minimal · up to 5cd2f

The documentation changes are consistent with the available reference and implementation evidence; no concrete issue remains that should block merging.

Architecture Summary

Architecture risk: 🔵 Low · up to 5cd2f

The change affects 21 systems.

Changed systems: tidb-lightning, tiflash, best-practices, faq, ai, br, dashboard, dynamic-config.md, encryption-at-rest.md, garbage-collection-configuration.md, grafana-tikv-dashboard.md, pd-configuration-file.md, performance-tuning-methods.md, sql-statements, tidb-performance-tuning-config.md, tidb-troubleshooting-map.md, tiflash-upgrade-guide.md, tikv-configuration-file.md, tikv-control.md, troubleshoot-high-disk-io.md, tune-tikv-thread-performance.md

Architecture concerns
No architecture-level concerns identified.

Review details

Systems and components

• observed — tidb-lightning (service) was modified; 4 changed files map to changed impact.
• observed — tiflash (service) was modified; 4 changed files map to changed impact.
• observed — best-practices (service) was modified; 2 changed files map to changed impact.
• observed — faq (service) was modified; 2 changed files map to changed impact.

Before / after behavior

• observed — Modified behavior in best-practices/best-practices-on-public-cloud.md: 見出しの「圧縮 I/O フロー」を「コンパクション I/O フロー」に変更しました。
• observed — Modified behavior in best-practices/best-practices-on-public-cloud.md: 平均行サイズが 512 バイトより大きい場合の Titan 設定について、説明中の「圧縮 I/O フロー」を「コンパクション I/O フロー」に変更しました。設定値と適用条件は変わっていません。
• observed — Modified behavior in best-practices/three-nodes-hybrid-deployment.md: rocksdb.max-sub-compactionsの説明で、単一ジョブの用語を「圧縮ジョブ」から「コンパクションジョブ」に変更しました。デフォルト値と、書き込み負荷が高くない場合に値を下げられるという説明は維持されています。
• observed — Modified behavior in best-practices/three-nodes-hybrid-deployment.md: rocksdb.rate-bytes-per-secの説明で、「バックグラウンド圧縮ジョブ」を「バックグラウンドコンパクションジョブ」に変更しました。帯域制限の説明は維持されています。

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the Japanese documentation terminology change for compaction and indicates that this is part 1.
Description check	✅ Passed	The description explains the terminology change, its rationale and scope, the affected documentation branch, and related reference information. It also addresses AI involvement and the applicable chec…
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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ℹ️ Review info

⚙️ Run configuration

• Configuration used: Repository: pingcap/docs/.coderabbit.yaml
• Review profile: ASSERTIVE
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• Run ID: 665b3282-0a00-4e89-bd6f-b2fae9b58346

📥 Commits

Reviewing files that changed from the base of the PR and between a4dfec7 and 7ca8164.

📒 Files selected for processing (29)

• ai/ti/reference/ti-configuration-and-credentials.md
• best-practices/best-practices-on-public-cloud.md
• best-practices/three-nodes-hybrid-deployment.md
• br/br-compact-log-backup.md
• dashboard/dashboard-monitoring.md
• dynamic-config.md
• encryption-at-rest.md
• faq/manage-cluster-faq.md
• faq/sql-faq.md
• garbage-collection-configuration.md
• grafana-tikv-dashboard.md
• pd-configuration-file.md
• performance-tuning-methods.md
• sql-statements/sql-statement-alter-table-compact.md
• tidb-lightning/data-import-best-practices.md
• tidb-lightning/import-into-vs-tidb-lightning.md
• tidb-lightning/tidb-lightning-command-line-full.md
• tidb-lightning/tidb-lightning-glossary.md
• tidb-performance-tuning-config.md
• tidb-troubleshooting-map.md
• tiflash-upgrade-guide.md
• tiflash/monitor-tiflash.md
• tiflash/tiflash-configuration.md
• tiflash/tune-tiflash-performance.md
• tiflash/use-fastscan.md
• tikv-configuration-file.md
• tikv-control.md
• troubleshoot-high-disk-io.md
• tune-tikv-thread-performance.md

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