Prevent the execution of clearBatch() when executeBatch throws an exception.

[erinerum]

When the executeBatch method is executed and the process throws an exception, the InputBasedPreparedStatement.executeAny method clears the content of the generated preparedStatement by invoking the clearBatch() method. This makes it impossible to create a retry system when the exception is generated by a recoverable issue.

In implementations where batches of more than one million elements are being processed, the most efficient way to store the data is directly in the driver's preparedStatement. This way, the data is saved serialized, saving a large amount of memory. The execution of the clearBatch method prevents this possibility and forces redundant data storage.

Adding the ability to include a property to disable automatic clearBatch when an exception occurs would make the driver offer more flexible solutions when performing huge numbers of insertions on the server.

[chernser]

@erinerum thank you for reporting the issue.

Btw, what is initial format from which data is getting to prepared statement? Is it possible to use plain java client with one of supported formats (like JSONEachRow) to stream data from input to server by passing JDBC complexity?

[erinerum]

Thank you for the quick response. The use of the JDBC client has been proposed as an additional abstraction layer. However, exploring the use of the Java client could be very interesting. Thank you for the suggestion!

[chernser]

@erinerum btw, there is a Slack Community where you may ask questions about ClickHouse https://clickhouse.com/slack
We are glad to help!