@Choolake See if this does the job for you. ... ROW FORMAT SERDE 'org.apache.hadoop.hive.contrib.serde2.JsonSerde' WITH SERDEPROPERTIES ( 'separatorChar' = '|', 'quoteChar' = '"' ) STORED AS TEXTFILE LOCATION .... This is a third party serde. You may download it from https://code.google.com/archive/p/hive-json-serde/downloads ... View more

Try this: CREATE external TABLE mytable ( col1 INT, col2 STRING, col3 STRING, col4 STRING, col5 INT, col6 STRING, col7 STRING ... ) ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.OpenCSVSerde' WITH SERDEPROPERTIES ( "separatorChar" = ",", "quoteChar" = "\"" ) STORED AS TEXTFILE; It should work. ... View more

@Leopold I just checked. Your observation is correct. For external tables, it does not use a fetch task. In the logs, I see the following message: 2024-03-12 10:48:37,247 INFO org.apache.hadoop.hive.ql.optimizer.StatsOptimizer: [b226e7aa-9a42-4af3-b99b-be4a6592fb7f HiveServer2-Handler-Pool: Thread-31145]: Table t7 is external. Skip StatsOptimizer. But enabling  "hive.fetch.task.aggr=true" will help avoid the Reducer phase that is used for final aggregation. It will be a Map-only job. ... View more