Caizhi Weng created FLINK-15570: ----------------------------------- Summary: Support inserting into non-empty csv tables Key: FLINK-15570 URL: https://issues.apache.org/jira/browse/FLINK-15570 Project: Flink Issue Type: Improvement Components: Connectors / FileSystem, Formats (JSON, Avro, Parquet, ORC, SequenceFile) Reporter: Caizhi Weng
Currently we only support inserting into empty csv tables. It would be nice for a new user from traditional database to try out Flink if we support inserting into non-empty csv tables. In other words, it would be nice if the following SQL produces a valid result: {code:java} CREATE TABLE myTable( a INT, b DOUBLE ) WITH ( 'connector.type' = 'filesystem', 'connector.path' = an existing csv file, 'format.type' = 'csv', 'format.derive-schema' = 'true' ); SELECT * FROM myTable; // produces 3 rows INSERT INTO myTable VALUES (4, 4.4); SELECT * FROM myTable; // produces 4 rows{code} We currently only have two write modes, namely NO_OVERWRITE and OVERWRITE. In NO_OVERWRITE mode we can only insert into empty csv tables, while in OVERWRITE mode inserting into a csv table will wipe all existing data in it (in the above example, the last SELECT will produce only 1 instead of 4 rows) which is really strange for a mere INSERT operation. We need to add a new APPEND write mode, or change the behavior for OVERWRITE mode to something like appending to files. -- This message was sent by Atlassian Jira (v8.3.4#803005)