How can I with help of monitoring tools check online the consumption of memory in particular transaction (resource usage)?
In order to be able to monitor online the memory consumption during execution of particular transaction you should turn on the memory consumption display. This can be achieved either via menu path: System –> Utilities –> Resource usage or typing in the command field “/$st”. Now, during the execution of transaction, you would be able to see how much roll, heap and extended memory are in use.