cdc: add table routing feature #23097
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This pull request introduces a new documentation page for TiCDC Table Routing and updates the table of contents. The feedback primarily focuses on improving clarity and readability by replacing passive voice with active voice throughout the document, as well as addressing minor grammatical and phrasing issues to align with the style guide.
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| | Storage services | Storage paths, schema files, table definition files, and data files use the target schema and table names. | | ||
| | Redo log | Redo records preserve the target schema and table names. When you apply redo logs, events are replayed to the routed target objects. | | ||
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| For MQ sinks, table routing does not change the topic or partition dispatch result. For example, if `topic = "{schema}_{table}"` and the source table is `sales.orders`, TiCDC still dispatches the event to the topic `sales_orders` even if the payload table name is routed to `archive.sales_orders`. |
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Use active voice to improve clarity and readability.
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| For MQ sinks, table routing does not change the topic or partition dispatch result. For example, if `topic = "{schema}_{table}"` and the source table is `sales.orders`, TiCDC still dispatches the event to the topic `sales_orders` even if the payload table name is routed to `archive.sales_orders`. | |
| For MQ sinks, table routing does not change the topic or partition dispatch result. For example, if `topic = "{schema}_{table}"` and the source table is `sales.orders`, TiCDC still dispatches the event to the topic `sales_orders` even if TiCDC routes the payload table name to `archive.sales_orders`. |
References
- Avoid passive voice overuse. Prefer active voice for clarity and readability. (link)
| RENAME TABLE `archive`.`temp_table_routed` TO `archive`.`renamed_table_routed`; | ||
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| If a DDL statement contains table references, TiCDC also rewrites the referenced table names when they match table routing rules. For example, table references in `CREATE VIEW` statements and foreign key references in `ALTER TABLE` statements can be routed. |
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Use active voice to improve clarity and readability.
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| If a DDL statement contains table references, TiCDC also rewrites the referenced table names when they match table routing rules. For example, table references in `CREATE VIEW` statements and foreign key references in `ALTER TABLE` statements can be routed. | |
| If a DDL statement contains table references, TiCDC also rewrites the referenced table names when they match table routing rules. For example, TiCDC can route table references in `CREATE VIEW` statements and foreign key references in `ALTER TABLE` statements. |
References
- Avoid passive voice overuse. Prefer active voice for clarity and readability. (link)
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| | `target-schema` | Specifies the downstream schema name. If this field is not set, TiCDC keeps the upstream schema name. | | ||
| | `target-table` | Specifies the downstream table name. If this field is not set, TiCDC keeps the upstream table name. | |
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Use active voice to improve clarity and readability. Avoid passive phrasing like 'is not set'.
Suggested change
| | `target-schema` | Specifies the downstream schema name. If this field is not set, TiCDC keeps the upstream schema name. | | |
| | `target-table` | Specifies the downstream table name. If this field is not set, TiCDC keeps the upstream table name. | | |
| | `target-schema` | Specifies the downstream schema name. If you do not set this field, TiCDC keeps the upstream schema name. | | |
| | `target-table` | Specifies the downstream table name. If you do not set this field, TiCDC keeps the upstream table name. | |
References
- Avoid passive voice overuse. Prefer active voice for clarity and readability. (link)
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| ## DDL behavior | ||
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| When table routing is enabled, TiCDC rewrites parser-supported DDL statements so that the structured DDL fields and the SQL text use the same target names. |
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Use active voice to improve clarity and readability.
Suggested change
| When table routing is enabled, TiCDC rewrites parser-supported DDL statements so that the structured DDL fields and the SQL text use the same target names. | |
| When you enable table routing, TiCDC rewrites parser-supported DDL statements so that the structured DDL fields and the SQL text use the same target names. |
References
- Avoid passive voice overuse. Prefer active voice for clarity and readability. (link)
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| - `sales.orders` is routed to `archive.orders_bak`. | ||
| - `sales.order_items` is routed to `archive.order_items_bak`. |
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Use active voice to improve clarity and readability.
Suggested change
| - `sales.orders` is routed to `archive.orders_bak`. | |
| - `sales.order_items` is routed to `archive.order_items_bak`. | |
| - TiCDC routes `sales.orders` to `archive.orders_bak`. | |
| - TiCDC routes `sales.order_items` to `archive.order_items_bak`. |
References
- Avoid passive voice overuse. Prefer active voice for clarity and readability. (link)
| - Table routing does not transform row values, column names, column types, or table schemas. | ||
| - `filter.rules`, `matcher`, `topic`, `partition`, and `columns` continue to use upstream schema and table names. | ||
| - Removing table routing configuration or rolling back TiCDC does not rename downstream tables, move storage files, rewrite MQ messages, or clean up redo logs that have already been generated with target names. | ||
| - If the source and target are in the same database instance, make sure that the routed target schemas are not included in the same changefeed replication scope. Otherwise, the changefeed might replicate its own downstream writes. |
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Use active voice to improve clarity and readability.
Suggested change
| - If the source and target are in the same database instance, make sure that the routed target schemas are not included in the same changefeed replication scope. Otherwise, the changefeed might replicate its own downstream writes. | |
| - If the source and target are in the same database instance, make sure that you do not include the routed target schemas in the same changefeed replication scope. Otherwise, the changefeed might replicate its own downstream writes. |
References
- Avoid passive voice overuse. Prefer active voice for clarity and readability. (link)
| - Table routing supports one-to-one table name mapping only. It does not support merging multiple upstream tables into one downstream table. | ||
| - Table routing does not transform row values, column names, column types, or table schemas. | ||
| - `filter.rules`, `matcher`, `topic`, `partition`, and `columns` continue to use upstream schema and table names. | ||
| - Removing table routing configuration or rolling back TiCDC does not rename downstream tables, move storage files, rewrite MQ messages, or clean up redo logs that have already been generated with target names. |
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Use active voice to improve clarity and readability.
Suggested change
| - Removing table routing configuration or rolling back TiCDC does not rename downstream tables, move storage files, rewrite MQ messages, or clean up redo logs that have already been generated with target names. | |
| - Removing table routing configuration or rolling back TiCDC does not rename downstream tables, move storage files, rewrite MQ messages, or clean up redo logs that TiCDC has already generated with target names. |
References
- Avoid passive voice overuse. Prefer active voice for clarity and readability. (link)
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| ## Limitations | ||
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| - Table routing supports one-to-one table name mapping only. It does not support merging multiple upstream tables into one downstream table. |
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Improve word order for better flow and clarity.
Suggested change
| - Table routing supports one-to-one table name mapping only. It does not support merging multiple upstream tables into one downstream table. | |
| - Table routing supports only one-to-one table name mapping. It does not support merging multiple upstream tables into one downstream table. |
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| If both `sales.orders` and `crm.orders` are in the replication scope, both tables are routed to `archive.orders`. TiCDC rejects the changefeed create or update operation and returns the `CDC:ErrTableRouteConflict` error. | ||
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| TiCDC also detects conflicts that appear after a changefeed starts. For example, if a wildcard rule starts replicating a newly created table, or a `RENAME TABLE` statement changes a source table name, and the new route result conflicts with an existing target table, the changefeed enters the failed state with `CDC:ErrTableRouteConflict`. |
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Simplify 'newly created table' to 'new table' to avoid unnecessary words, as per the style guide.
Suggested change
| TiCDC also detects conflicts that appear after a changefeed starts. For example, if a wildcard rule starts replicating a newly created table, or a `RENAME TABLE` statement changes a source table name, and the new route result conflicts with an existing target table, the changefeed enters the failed state with `CDC:ErrTableRouteConflict`. | |
| TiCDC also detects conflicts that appear after a changefeed starts. For example, if a wildcard rule starts replicating a new table, or a `RENAME TABLE` statement changes a source table name, and the new route result conflicts with an existing target table, the changefeed enters the failed state with `CDC:ErrTableRouteConflict`. |
References
- Avoid unnecessary words and repetition. (link)
| | `{schema}` | The upstream schema name. | | ||
| | `{table}` | The upstream table name. | | ||
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| The value of `target-schema` and `target-table` can contain only literal text, `{schema}`, and `{table}`. If you use an unknown placeholder such as `{db}`, TiCDC rejects the changefeed configuration and returns the `CDC:ErrInvalidTableRoutingRule` error. |
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Use plural 'values' since it refers to two fields: target-schema and target-table.
Suggested change
| The value of `target-schema` and `target-table` can contain only literal text, `{schema}`, and `{table}`. If you use an unknown placeholder such as `{db}`, TiCDC rejects the changefeed configuration and returns the `CDC:ErrInvalidTableRoutingRule` error. | |
| The values of `target-schema` and `target-table` can contain only literal text, `{schema}`, and `{table}`. If you use an unknown placeholder such as `{db}`, TiCDC rejects the changefeed configuration and returns the `CDC:ErrInvalidTableRoutingRule` error. |
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