What is the purpose of the OAUTH_CLIENT_TOKEN table in a Spring Oauth2 JDBC implementation

Question

Do you know what is the purpose of the OAUTH_CLIENT_TOKEN table in a JDBC implementation of a Spring Oauth2 server ?

It seems that the table is never populated, however when a client obtains a token using "client credentials", its token is saved into OAUTH_ACCESS_TOKEN and not into OAUTH_CLIENT_TOKEN with a null username.

Here is the tables schemas very similar actually.

drop table if exists oauth_client_token;
create table oauth_client_token
(
    token_id          VARCHAR(255),
    token             LONGBLOB,
    authentication_id VARCHAR(255),
    user_name         VARCHAR(255),
    client_id         VARCHAR(255)
);

drop table if exists oauth_access_token;
create table `oauth_access_token`
(
    token_id          VARCHAR(255),
    token             LONGBLOB,
    authentication_id VARCHAR(255) PRIMARY KEY,
    user_name         VARCHAR(255),
    client_id         VARCHAR(255),
    authentication    LONGBLOB,
    refresh_token     VARCHAR(255)
);

Also the configuration into the AuthorizationServerConfigurerAdapter

@Bean
public JdbcClientTokenServices clientTokenServices() {
    return new JdbcClientTokenServices(this.dataSource);
}

@Bean
public TokenStore tokenStore() {
    return new JdbcTokenStore(this.dataSource);
}

Answer 1

That table doesn't seem to be used anymore. The legacy Spring oauth2 authorization server will reach end of live in may 22.