public String getDeleteEventExecutionsStatement() {
        return QueryBuilder.delete()
                .from(keyspace, TABLE_EVENT_EXECUTIONS)
                .where(eq(MESSAGE_ID_KEY, bindMarker()))
                .and(eq(EVENT_HANDLER_NAME_KEY, bindMarker()))
                .and(eq(EVENT_EXECUTION_ID_KEY, bindMarker()))
                .getQueryString();
    }
@return cql query statement to delete an event execution from the "event_execution" table
cassandra-persistence/src/main/java/com/netflix/conductor/cassandra/util/Statements.java