@Override
    public DynamicTableSource copy() {
        SqlServerTableSource source =
                new SqlServerTableSource(
                        physicalSchema,
                        port,
                        hostname,
                        database,
                        schemaName,
                        tableName,
                        serverTimeZone,
                        username,
                        password,
                        dbzProperties,
                        startupOptions,
                        metricOption);
        source.metadataKeys = metadataKeys;
        source.producedDataType = producedDataType;
        return source;
    }
Metadata that is appended at the end of a physical source row.
inlong-sort/sort-flink/sort-flink-v1.15/sort-connectors/sqlserver-cdc/src/main/java/org/apache/inlong/sort/sqlserver/SqlServerTableSource.java