Consider the following database tables of a sports league. player (\( pid \), \( pname \), \( age \)) coach (\( cid \), \( cname \)) team (\( tid \), \( tname \), \( city \), \( cid \)) members (\( pid \), \( tid \)) An instance of the table and an SQL query are given. Player table
coach table:
team table:
members table:
SQL query: \[ {SELECT MIN(P.age)} \] \[ {FROM player P} \] \[ {WHERE P.pid IN (} \] \[ { SELECT M.pid} \] \[ { FROM team T, coach C, members M} \] \[ { WHERE C.cname = 'Mark'} \] \[ { AND T.cid = C.cid} \] \[ { AND M.tid = T.tid)} \] The value returned by the given SQL query is __________. (Answer in integer)
A schedule of three database transactions \(T_1\), \(T_2\), and \(T_3\) is shown. \(R_i(A)\) and \(W_i(A)\) denote read and write of data item A by transaction \(T_i\), \(i = 1, 2, 3\). The transaction \(T_1\) aborts at the end. Which other transaction(s) will be required to be rolled back?
