When two transactions compete for the same record, what does each lock mode S, E, X, and O allow?

When do dynamic work processes start and stop, and how many does the system add at startup?

Which OS command tests the message-server connection and lists available instances and logon groups?

When you define a lock object in the data dictionary, what gets generated automatically?

What does the _SCOPE parameter control on a lock, and what do values 1, 2, and 3 mean?

How can a single multi-screen transaction end up processed by several different dialog work processes?

What do the four ACID properties mean for an SAP LUW?