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  1. Debezium
  2. DBZ-1694

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

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      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');
      
      
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      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' );

    Description

      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.

      Attachments

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

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            jpechane Jiri Pechanec
            jasontsao0411 Jason Tsao (Inactive)
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              Created:
              Updated:
              Resolved: