midterm2-solution - CSCI485 Fall 2007 Midterm II Name 1...

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CSCI485 – Fall 2007 Midterm II Name_____________________ 1. What does atomicity requirement of a transaction imply? (5 points) Either all operations of the transaction are reflected properly in the DB, or none are 2. What does it mean for redo and undo operations to be idempotent? (5 points) Executing them several times must be equivalent to executing them once 3. Assume a 2 bit machine that implements an extendible hash index structure. Assume the capacity of each bucket is 2 records. Starting with an empty table (and index), show the structure of the directory after the insertion of each of the following (key,value) pairs: (10 points) (10,v1) (00,v2) (10,v3) (01,v4) (01,v5) (01,v6)
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Given the Emp table that maintains all employees of a company where each employee reports to a manager: Emp (SS#, name, age, salary, dept, mgrSS#). Assume this company has 100,000 employees with 10 records per disk page: t(Emp) = 100,000, P(Emp) = 10,000. When this table is joined with itself, the length of each record will be twice the original. Hence, only 5 such records fit per disk page. The maximum and minimum salary is 130,000 and 30,000 respectively; max(salary,Emp) = 130,000, min(salary,Emp)=30,000. SS# is unique with 100,000 distinct values, ν (SS#,Emp)=100,000. 4.
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This note was uploaded on 01/11/2009 for the course CSCI 485 taught by Professor Ghandeharizadeh during the Fall '08 term at USC.

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midterm2-solution - CSCI485 Fall 2007 Midterm II Name 1...

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