Hi devs,
Recently I am testing Kafka Source. And I find the if we not set `schema`
option. it will give a default schema. When use this default schema, the final
data is different with original.
If we not set `schema` option, it will set a default schema, type is
`content<Row<content<String>>>` [1]
Then if the kafka have record like this
```
abcde
xyz
```
And use this config to run a job.
```
env {
parallelism = 1
job.mode = "BATCH"
}
source {
Kafka {
plugin_output = "fake1"
format = text
topic = “test_topic"
bootstrap.servers = ""
start_mode = "earliest"
kafka.config = {
client.id = client_1
max.poll.records = 500
auto.offset.reset = "earliest"
enable.auto.commit = "false"
}
}
}
transform {
}
sink {
Console {
plugin_input = "fake1"
}
}
```
The result will be
```
sink.ConsoleSinkWriter - subtaskIndex=0 rowIndex=1:
SeaTunnelRow#tableId=Optional[test_topic] SeaTunnelRow#kind=INSERT : [abcde]
sink.ConsoleSinkWriter - subtaskIndex=0 rowIndex=1:
SeaTunnelRow#tableId=Optional[test_topic] SeaTunnelRow#kind=INSERT : [xyz]
```
It will add `[]` to the original value.
Can someone explain why it was designed this way?
I rise a pr [2] to update the default schema to `content<String>`, after this
pr the above job result will be same with original value.
Please let me know if you have any questions.
[1]
https://github.com/apache/seatunnel/blob/dev/seatunnel-connectors-v2/connector-kafka/src/main/java/org/apache/seatunnel/connectors/seatunnel/kafka/source/KafkaSourceConfig.java#L208
[2] https://github.com/apache/seatunnel/pull/8642/files
—
Best Regards
Jarvis
