Oracle update batching settings are disabled in Oracle Database 12c release 2 (12.2). Use JDBC batching instead.
Oracle update batching was deprecated in Oracle Database 12c Release 1 (12.1). Starting in Oracle Database 12c Release 2 (12.2), Oracle update batching is a no operation code (no-op). This means that if you implement Oracle update batching in your application using the Oracle Database 12c Release 2 (12.2) JDBC driver, then the specified batch size is not set, and results in a batch size of 1. With this batch setting, your application processes one row at a time. Oracle strongly recommends that you use the standard JDBC batching if you are using the Oracle Database 12c Release 2 (12.2) JDBC driver.