Why can't ICF services be called directly by default, and how do you enable them?

How many message servers does an SAP system have, and what is its main responsibility?

In HANA's multitenant architecture, what is the special responsibility of the SYSTEMDB?

An in-memory database (IMDB) keeps data in main memory rather than on disk — what two inevitable consequences follow?

In the command field, what do the `/N`, `/O`, and `/NEX` prefixes do?

What is the difference between Open SQL and Native SQL, and what role does the DBI play?

Into what intermediate form is ABAP source compiled before execution, and where is it stored?