TiCDC fill the default value without consider the real data type

[3AceShowHand]

What did you do?

create table t (a int primary key, b varchar(100));

insert into t values (1, "nitto");
insert into t values (2, "hotd");

alter table t add column c int default 17;

update t set b = "earth" where a = 1;

delete from t where a = 4;

What did you expect to see?

The old value part for the column c, should have type int, instead of string

What did you see instead?

For both update and delete event, the old value is encoded as string, instead of real data type int. Since TiDB and TiCDC stores the default value as string, and TiCDC just use that value without considering the column data type.

Versions of the cluster

Upstream TiDB cluster version (execute SELECT tidb_version(); in a MySQL client):

(paste TiDB cluster version here)

Upstream TiKV version (execute tikv-server --version):

(paste TiKV version here)

TiCDC version (execute cdc version):

master