public MetadataConverter getConverter() {
        return converter;
    }
get meta info from debezium-json data stream

@param record source record
@param tableNameKey key in the source record
@return value of the key in the source record
inlong-sort/sort-flink/sort-flink-v1.13/sort-connectors/postgres-cdc/src/main/java/org/apache/inlong/sort/cdc/postgres/table/PostgreSQLReadableMetaData.java