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Schema evolution

Schema Evolution means that the schema of a data table can be changed and the data synchronization task can automatically adapt to the changes of the new table structure without any other operations. Now we only support the operation about add columndrop columnrename column and modify column of the table in CDC source. This feature is only support zeta engine at now.

Supported connectors

Source

Mysql-CDC Oracle-CDC

Sink

Jdbc-Mysql Jdbc-Oracle

Note: The schema evolution is not support the transform at now. The schema evolution of different types of databases(Oracle-CDC -> Jdbc-Mysql)is currently not supported the default value of the column in ddl.

When you use the Oracle-CDC,you can not use the username named SYS or SYSTEM to modify the table schema, otherwise the ddl event will be filtered out which can lead to the schema evolution not working. Otherwise, If your table name start with ORA_TEMP_ will also has the same problem.

Enable schema evolution

Schema evolution is disabled by default in CDC source. You need configure debezium.include.schema.changes = true which is only supported in CDC to enable it. When you use Oracle-CDC with schema-evolution enabled, you must specify redo_log_catalog as log.mining.strategy in the debezium attribute.

Examples

Mysql-CDC -> Jdbc-Mysql

env {
# You can set engine configuration here
parallelism = 5
job.mode = "STREAMING"
checkpoint.interval = 5000
read_limit.bytes_per_second=7000000
read_limit.rows_per_second=400
}

source {
MySQL-CDC {
server-id = 5652-5657
username = "st_user_source"
password = "mysqlpw"
table-names = ["shop.products"]
base-url = "jdbc:mysql://mysql_cdc_e2e:3306/shop"
debezium = {
include.schema.changes = true
}
}
}

sink {
jdbc {
url = "jdbc:mysql://mysql_cdc_e2e:3306/shop"
driver = "com.mysql.cj.jdbc.Driver"
user = "st_user_sink"
password = "mysqlpw"
generate_sink_sql = true
database = shop
table = mysql_cdc_e2e_sink_table_with_schema_change_exactly_once
primary_keys = ["id"]
is_exactly_once = true
xa_data_source_class_name = "com.mysql.cj.jdbc.MysqlXADataSource"
}
}

Oracle-cdc -> Jdbc-Oracle

env {
# You can set engine configuration here
parallelism = 1
job.mode = "STREAMING"
checkpoint.interval = 5000
}

source {
# This is a example source plugin **only for test and demonstrate the feature source plugin**
Oracle-CDC {
result_table_name = "customers"
username = "dbzuser"
password = "dbz"
database-names = ["ORCLCDB"]
schema-names = ["DEBEZIUM"]
table-names = ["ORCLCDB.DEBEZIUM.FULL_TYPES"]
base-url = "jdbc:oracle:thin:@oracle-host:1521/ORCLCDB"
source.reader.close.timeout = 120000
connection.pool.size = 1
debezium {
include.schema.changes = true
log.mining.strategy = redo_log_catalog
}
}
}

sink {
Jdbc {
source_table_name = "customers"
driver = "oracle.jdbc.driver.OracleDriver"
url = "jdbc:oracle:thin:@oracle-host:1521/ORCLCDB"
user = "dbzuser"
password = "dbz"
generate_sink_sql = true
database = "ORCLCDB"
table = "DEBEZIUM.FULL_TYPES_SINK"
batch_size = 1
primary_keys = ["ID"]
connection.pool.size = 1
}
}

Oracle-cdc -> Jdbc-Mysql

env {
# You can set engine configuration here
parallelism = 1
job.mode = "STREAMING"
checkpoint.interval = 5000
}

source {
# This is a example source plugin **only for test and demonstrate the feature source plugin**
Oracle-CDC {
result_table_name = "customers"
username = "dbzuser"
password = "dbz"
database-names = ["ORCLCDB"]
schema-names = ["DEBEZIUM"]
table-names = ["ORCLCDB.DEBEZIUM.FULL_TYPES"]
base-url = "jdbc:oracle:thin:@oracle-host:1521/ORCLCDB"
source.reader.close.timeout = 120000
connection.pool.size = 1
debezium {
include.schema.changes = true
log.mining.strategy = redo_log_catalog
}
}
}

sink {
jdbc {
source_table_name = "customers"
url = "jdbc:mysql://oracle-host:3306/oracle_sink"
driver = "com.mysql.cj.jdbc.Driver"
user = "st_user_sink"
password = "mysqlpw"
generate_sink_sql = true
# You need to configure both database and table
database = oracle_sink
table = oracle_cdc_2_mysql_sink_table
primary_keys = ["ID"]
}
}