Full exam for Data Bases 2 in the Computer Engineering degree programme at Politecnico di Milano. The document covers: Check if 30% reduction: ◻ Last name: First name: Pers. code: Signature: Databases 2 - exam - February 12, 2024 - Dur. 2h S. Comai, P. Fraternali, D. Martinenghi Students with 30% reduction can omit: Question B.2. A. Concurrency control (8 points) Apply the distributed deadlock
Full exam for Data Bases 2 in the Computer Engineering degree programme at Politecnico di Milano. The document covers: Check if 30% reduction: ◻ Last name: First name: Pers. code: Signature: Databases 2 - exam - February 12, 2024 - Dur. 2h S. Comai, P. Fraternali, D. Martinenghi Students with 30% reduction can omit: Question B.2. A. Concurrency control (8 points) Apply the distributed deadlock
Import quality: text was extracted directly from the original document.
Representative passages recognised in different parts of the material. The full extracted text remains available to search, while this compact preview makes the page easier to read.
Check if 30% reduction: ◻ Last name: First name: Pers. code: Signature: Databases 2 - exam - February 12, 2024 - Dur. 2h S. Comai, P. Fraternali, D. Martinenghi Students with 30% reduction can omit: Question B.2. A. Concurrency control (8 points) Apply the distributed deadlock detection algorithm to the following wait-for conditions using two conven- tions: 1) a dependency ti → tj can be transmitted (forward) if i > jif i > jif i > jif i > jif i > jif i > jif i > jif i > jif i > jif i > jif i > jif i > jif i > jif i > jif i > jif i > jif i > j; 2) a dependency ti → tj can be transmitted (forward) if i < jif i < jif i < jif i < jif i < jif i < jif i < jif i < jif i < jif i < jif i < jif i < jif i < jif i < jif i < jif i < jif i < j; • Node A: EC → t4; t4 → t7; t7 → t5; t5 → EB; • Node B: EA → t5; t5 → t6; t6 → t1; t1 → EC; • Node C: EB → t1; t1 → t3; t3 → t2; t3 → t4; t4 → EA. For each convention, execute all the steps, reporting all the messages that are sent during the process. B. T riggers (12 points) Consider the following relational schema: PROJECT(PIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPID, name, duration) EMP(EIDEIDEIDEIDEIDEIDEIDEIDEIDEIDEIDEIDEIDEIDEIDEIDEID, name, salary) ASSIGNMENT(PID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EIDPID, EID) where PID and EID in ASSIGNMENT are under foreign key constraints to PROJECT and EMP, respectively. Your task is to define a set of triggers that maintain a table BUDGET(PIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPIDPID, cost) with the same content as would be maintained by the following view: CREATE VIEW budget AS SELECT P.PID, COALESCE (SUM(salary), 0) AS cost FROM project P LEFT JOIN assignment A ON P.PID = A.PID LEFT JOIN emp E ON…
First page of the document.
