Uploaded image for project: 'Debezium'
  1. Debezium
  2. DBZ-1694

CDC Event Schema Doesn't Change After 2 Fields Switch Names and Places

XMLWordPrintable

    • Hide

      MySQL docker image: percona:5.7

      CREATE TABLE `test_table` (
  `c1` int NOT NULL,
  `c2` int NOT NULL,
  `c3` int NOT NULL
);
-- Insert some data, Debezium CDC event has schema v1
INSERT INTO `test_table` (`c1`, `c2`, `c3`)
VALUES ('1', '11', '111');

-- Switch 2 columns names and places
ALTER TABLE `test_table`
CHANGE `c3` `c3_temp` int(11) NOT NULL AFTER `c1`,
CHANGE `c2` `c2_temp` int(11) NOT NULL AFTER `c3_temp`;

ALTER TABLE `test_table`
CHANGE `c3_temp` `c2` int(11) NOT NULL AFTER `c1`,
CHANGE `c2_temp` `c3` int(11) NOT NULL AFTER `c2`;

-- Insert some data, but Debezium CDC event still has schema v1
INSERT INTO `test_table` (`c1`, `c2`, `c3`)
VALUES ('2', '22', '222');
      Show
      MySQL docker image: percona:5.7 CREATE TABLE `test_table` ( `c1` int NOT NULL , `c2` int NOT NULL , `c3` int NOT NULL ); -- Insert some data , Debezium CDC event has schema v1 INSERT INTO `test_table` (`c1`, `c2`, `c3`) VALUES ( '1' , '11' , '111' ); -- Switch 2 columns names and places ALTER TABLE `test_table` CHANGE `c3` `c3_temp` int (11) NOT NULL AFTER `c1`, CHANGE `c2` `c2_temp` int (11) NOT NULL AFTER `c3_temp`; ALTER TABLE `test_table` CHANGE `c3_temp` `c2` int (11) NOT NULL AFTER `c1`, CHANGE `c2_temp` `c3` int (11) NOT NULL AFTER `c2`; -- Insert some data , but Debezium CDC event still has schema v1 INSERT INTO `test_table` (`c1`, `c2`, `c3`) VALUES ( '2' , '22' , '222' );

      In MySQL, between 2 CDC events, if the table has 2 columns renamed and switched positions, the CDC events will have the same schema before and after the schema change.

      In the attachments are the CDC events before and after schema changes.

        1. after.json
          4 kB
        2. before.json
          4 kB

            jpechane Jiri Pechanec
            jasontsao0411 Jason Tsao (Inactive)
            Votes:
            0 Vote for this issue
            Watchers:
            3 Start watching this issue

              Created:
              Updated:
              Resolved: