????????kafka table????????scan.startup.mode CREATE TABLE kafkaTable (
user_id BIGINT, item_id BIGINT, category_id BIGINT, behavior STRING, ts
TIMESTAMP(3) ) WITH ( 'connector' = 'kafka', 'topic' = 'user_behavior',
'properties.bootstrap.servers' = 'localhost:9092', 'properties.group.id' =
'testGroup', 'format' = 'csv', 'scan.startup.mode' = 'earliest-offset'
)??????????????????'earliest-offset', 'latest-offset', 'group-offsets', 'timestamp' and 'specific-offsets'??????????????????????group-offsets??????????????????????????????????????????????????offset??kafka
broker??????????????????????savepoint??????offset????????????????
