ticdc: document ignore-update-only-columns filter by lidezhu · Pull Request #23523 · pingcap/docs

lidezhu · 2026-08-13T09:40:57Z

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This PR is translated from: ticdc: document ignore-update-only-columns filter docs-cn#21883
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Summary by CodeRabbit

New Features
- Added the ignore-update-only-columns event-filter option for Kafka changefeeds.
- UPDATE events are filtered when only configured columns change, except when primary or unique keys are modified.
- Added OpenAPI support for configuring and viewing this option, introduced in v8.5.9.
Documentation
- Documented case sensitivity, invalid-column warnings, and behavior for non-Kafka downstreams, which accept the setting but do not apply the filter.

coderabbitai · 2026-08-13T09:41:23Z

No actionable comments were generated in the recent review. 🎉

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📥 Commits

Reviewing files that changed from the base of the PR and between 999e668 and 1f589d1.

📒 Files selected for processing (3)

ticdc/ticdc-changefeed-config.md
ticdc/ticdc-filter.md
ticdc/ticdc-open-api-v2.md

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📝 Walkthrough

Walkthrough

The documentation adds the Kafka-only ignore-update-only-columns filter, its matching rules, and its exceptions. OpenAPI v2 examples now include the option in create, response, and update configurations.

Changes

TiCDC filter documentation

Layer / File(s)	Summary
Document filter behavior `ticdc/ticdc-changefeed-config.md`, `ticdc/ticdc-filter.md`, `ticdc/ticdc-open-api-v2.md`	Documents the filter syntax, Kafka-only behavior, update-column matching, key-column exceptions, case sensitivity, and nonexistent-column handling.
Update OpenAPI configuration schemas `ticdc/ticdc-open-api-v2.md`	Adds `ignore_update_only_columns` to create, response, and update replication-task configuration examples.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Merge Risk: 🔵 Low · up to 1f589

The PR documents the new filter but omits the exception for updates involving primary or unique key columns, which could mislead users about when events are filtered. The change is mergeable with explicit owner follow-up to align the API description with the documented behavior.

Suggested reviewers: qiancai

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The description selects the affected versions and provides the translation link, but it leaves the required change summary empty.	Add a concise summary that explains what changed and why, including the documented TiCDC filter behavior.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the TiCDC documentation change for the ignore-update-only-columns filter.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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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Commit unit tests in branch ldz/add-ignore-update-config

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Actionable comments posted: 1

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📥 Commits

Reviewing files that changed from the base of the PR and between 97bbec4 and 999e668.

📒 Files selected for processing (3)

ticdc/ticdc-changefeed-config.md
ticdc/ticdc-filter.md
ticdc/ticdc-open-api-v2.md

coderabbitai · 2026-08-13T09:43:43Z

 | `ignore_sql`                   | `STRING ARRAY` type. For example, `["^drop", "add column"]` means to filter out DDL statements that start with `DROP` or contain `ADD COLUMN`. (Optional)  |
 | `ignore_update_new_value_expr` | `STRING ARRAY` type. For example, `"gender = 'male'"` means to filter out the UPDATE DML statements with the new value `gender = 'male'`. (Optional)          |
 | `ignore_update_old_value_expr` | `STRING ARRAY` type. For example, `"age < 18"` means to filter out the UPDATE DML statements with the old value `age < 18`. (Optional)                  |
+| `ignore_update_only_columns`   | `STRING ARRAY` type. Introduced in v8.5.8 and applicable only to Kafka downstreams. If all columns whose values are changed in an UPDATE event are included in this array, TiCDC filters out the event. For example, `["version", "updated_at"]`. (Optional) |


🗄️ Data Integrity & Integration | 🟡 Minor | ⚡ Quick win

Document the primary/unique-key exception.

Line 298 states that every matching update is filtered. This conflicts with ticdc/ticdc-filter.md: TiCDC does not filter the event when a changed column is a primary key or unique key column.

As per path instructions: “For every actionable issue, provide a GitHub committable suggestion block when the fix can be safely applied to contiguous lines.”

Apply this suggestion

Suggested change

| `ignore_update_only_columns` | `STRING ARRAY` type. Introduced in v8.5.8 and applicable only to Kafka downstreams. If all columns whose values are changed in an UPDATE event are included in this array, TiCDC filters out the event. For example, `["version", "updated_at"]`. (Optional) |

| `ignore_update_only_columns` | `STRING ARRAY` type. Introduced in v8.5.8 and applicable only to Kafka downstreams. If all columns whose values are changed in an `UPDATE` event are included in this array, TiCDC filters out the event, except when the event changes a primary key or unique key column. For example, `["version", "updated_at"]`. (Optional) |

Source: Path instructions

CLAassistant · 2026-08-14T09:50:36Z

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ti-chi-bot · 2026-08-18T09:07:27Z

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ticdc: document ignore-update-only-columns filter

999e668

ti-chi-bot Bot added missing-translation-status This PR does not have translation status info. size/S Denotes a PR that changes 10-29 lines, ignoring generated files. labels Aug 13, 2026

coderabbitai Bot reviewed Aug 13, 2026

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lilin90 added the translation/done This PR has been translated from English into Chinese and updated to pingcap/docs-cn in a PR. label Aug 13, 2026

ti-chi-bot Bot removed the missing-translation-status This PR does not have translation status info. label Aug 13, 2026

lilin90 self-assigned this Aug 13, 2026

lilin90 added area/ticdc Indicates that the Issue or PR belongs to the area of TiCDC. needs-cherry-pick-release-8.5 Should cherry pick this PR to release-8.5 branch. labels Aug 13, 2026

lilin90 reviewed Aug 18, 2026

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Comment thread ticdc/ticdc-changefeed-config.md Outdated

Comment thread ticdc/ticdc-filter.md Outdated

Comment thread ticdc/ticdc-open-api-v2.md Outdated

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1f589d1

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ticdc: document ignore-update-only-columns filter - #23523

ticdc: document ignore-update-only-columns filter#23523
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	\| `ignore_update_only_columns` \| `STRING ARRAY` type. Introduced in v8.5.8 and applicable only to Kafka downstreams. If all columns whose values are changed in an UPDATE event are included in this array, TiCDC filters out the event. For example, `["version", "updated_at"]`. (Optional) \|
	\| `ignore_update_only_columns` \| `STRING ARRAY` type. Introduced in v8.5.8 and applicable only to Kafka downstreams. If all columns whose values are changed in an `UPDATE` event are included in this array, TiCDC filters out the event, except when the event changes a primary key or unique key column. For example, `["version", "updated_at"]`. (Optional) \|

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