execute

fun execute(sql: String, ignoreRows: Boolean = false)

Uses Simple Query Protocol (Q). Intended for calls that do not return results or where results are ignored (e.g., SET TIME ZONE, BEGIN).

Rows are read and dropped whatever ignoreRows says - the exchange has to reach ReadyForQueryMessage before this connection is usable again, and that means draining whatever the server sent. What ignoreRows governs is only whether their arrival is reported as a mistake.