DB SessionManager and CriticalSection

One question. Why do you use Critical Sections in uRODBEvenRepository in methods DoFindSession, DoGetSessionCount, DoDeleteSession, etc. ?
I understand that it is used in InMemorySessionManager but in DBSessionManager with TDataAbstract Pool?

if several clients call service methods simultaneously, it is possible that DoFindSession will be called from different background threads in the same time. Critical section protects this case.

I’m sorry but I do not understand the problem of executing this method with a DataAbstract Pool

Sorry, my fault, I was looking at uRODBSessionManager instead of uDADBSessionManager