When a race is run a number of tables need to update.
Results(EventID,CompID)
Medals(EventID,Medal,CompID)
medal is "Gold","Silver" or "Bronze"
MedalTally(Country,Medal,Number)
Competitors(CompID,Country)
Medalists(CompID,NMedals)
NMedals is total of medals for that Competitor
Suppose that when the event is completed at the venue giving CompID and position related with that EventID, then series of transactions are executed which update table shown.
a. for each table argue whether or not interference with another transaction is possible. Illustrate concurrency control method using two phase locking
b. Is there any situations in which DBMS would have to abort transaction?