TiCDC CSV Protocol

When using a cloud storage service as the downstream sink, you can send DML events to the cloud storage service in CSV format.

Use CSV

The following is an example of the configuration when using the CSV protocol:

cdc cli changefeed create --server=http://127.0.0.1:8300 --changefeed-id="csv-test" --sink-uri="s3://bucket/prefix" --config changefeed.toml

The configuration in the changefeed.toml file is as follows:

[sink]
protocol = "csv"
terminator = "\n"

[sink.csv]
delimiter = ',' # Before v7.6.0, you can only set the delimiter to a single character. Starting from v7.6.0, you can set it to 1-3 characters. For example, `$^` or `|@|`.
quote = '"'
null = '\N'
include-commit-ts = true
output-old-value = false

Transactional constraints

• In a single CSV file, the commit-ts of a row is equal to or smaller than that of the subsequent row.
• The same transactions of a single table are stored in the same CSV file.
• Multiple tables of the same transaction can be stored in different CSV files.

Data storage path structure

For more information about the storage path structure of the data, see Storage path structure.

Definition of the data format

In the CSV file, each column is defined as follows:

• Column 1: The operation-type indicator, including I, U, and D. I means INSERT, U means UPDATE, and D means DELETE.
• Column 2: Table name.
• Column 3: Schema name.
• Column 4: The commit-ts of the source transaction. This column is optional.
• Column 5: The is-update column only exists when the value of output-old-value is true, which is used to identify whether the row data change comes from the UPDATE event (the value of the column is true) or the INSERT/DELETE event (the value is false).
• Column 6 to the last column: One or more columns with data changes.

Assume that table hr.employee is defined as follows:

CREATE TABLE `employee` (
  `Id` int NOT NULL,
  `LastName` varchar(20) DEFAULT NULL,
  `FirstName` varchar(30) DEFAULT NULL,
  `HireDate` date DEFAULT NULL,
  `OfficeLocation` varchar(20) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

When include-commit-ts = true and output-old-value = false, the DML events of this table are stored in the CSV format as follows:

"I","employee","hr",433305438660591626,101,"Smith","Bob","2014-06-04","New York"
"U","employee","hr",433305438660591627,101,"Smith","Bob","2015-10-08","Los Angeles"
"D","employee","hr",433305438660591629,101,"Smith","Bob","2017-03-13","Dallas"
"I","employee","hr",433305438660591630,102,"Alex","Alice","2017-03-14","Shanghai"
"U","employee","hr",433305438660591630,102,"Alex","Alice","2018-06-15","Beijing"

When include-commit-ts = true and output-old-value = true, the DML events of this table are stored in the CSV format as follows:

"I","employee","hr",433305438660591626,false,101,"Smith","Bob","2014-06-04","New York"
"D","employee","hr",433305438660591627,true,101,"Smith","Bob","2015-10-08","Shanghai"
"I","employee","hr",433305438660591627,true,101,"Smith","Bob","2015-10-08","Los Angeles"
"D","employee","hr",433305438660591629,false,101,"Smith","Bob","2017-03-13","Dallas"
"I","employee","hr",433305438660591630,false,102,"Alex","Alice","2017-03-14","Shanghai"
"D","employee","hr",433305438660591630,true,102,"Alex","Alice","2017-03-14","Beijing"
"I","employee","hr",433305438660591630,true,102,"Alex","Alice","2018-06-15","Beijing"

Data type mapping