COSC 3380 Exam 3 Questions and Answers Already Passed

COSC 3380 Exam 3 Questions and Answers Already Passed Reading one gigabyte takes about one second. - Answers Flash memory Used to store petabytes (millions of gigabytes) of user data in the cloud. - Answers Magnetic disk Upgrading from 16 to 32 gigabytes costs an extra $400 for an Apple laptop computer. - Answers Main memory Approximately how many sectors are required to store one megabyte of data? Always 8,000 Always 2,000 Either 250 or 2,000 - Answers Either 250 or 2000 The database administrator specifies an eight-kilobyte block size. Flash memory page size is two kilobytes. A user runs a query that reads two pages of flash memory. How many blocks are transferred to main memory? - Answers One A database uses 16-kilobyte blocks. A table contains 18,200 rows of 100 bytes each. Ignoring space used by the system for overhead, how many bytes are unused on each block? Assume one kilobyte = 1,024 bytes. None 84 384 - Answers 84 4-megabyte photographs are usually stored ____. - Answers separate from other columns, managed either within the database or by the file system Assume column-oriented storage. Roughly how many blocks are required to compute average income by postal code for all people? - Answers 3250 blocks Assume row-oriented storage, with each row containing Name, Income, and PostalCode only. Roughly how many blocks are required to compute average income by postal code for all people? - Answers 8264 blocks The term 'column-oriented' ____. - Answers means either a technique for organizing data on storage media or a type of NoSQL database How many tables can be stored in one tablespace? A least zero, at most one At least zero, at most many At least one, at most many - Answers At least zero, at most many The Airport table has two thousand rows. The Airline table has ten thousand rows. Both tables are updated infrequently. Should Airport and Airline be stored in the same tablespace? - Answers Sometimes The Booking table has ten million rows and is updated frequently. The Airline table has ten thousand rows and is updated infrequently. Should Booking and Airline be stored in the same tablespace? - Answers Never How many partitions can one table have? At least zero, at most many At least one, at most many Always many - Answers At least zero, at most many The Airport table has two thousand rows and is updated infrequently. Should Airport be partitioned? Always Sometimes Never - Answers Never The Reservation table has one hundred million rows and is updated frequently. Most queries access recent bookings. Should Reservation be partitioned? Yes, Reservation should be partitioned on the ReservationDate column Yes, Reservation should be partitioned on the FlightNumber column No - Answers Yes, Reservation should be partitioned on the ReservationDate column Assume 100 rows fit in each block of a sorted table. If a block is full and an insert causes the block to split, roughly what percentage of the new and old blocks is empty? 33% 50% 90% - Answers 50% A database designer creates a new Employee table with primary key 'EmployeeNumber', loads 1 million rows into the table, then runs many queries that join other tables on the EmployeeNumber column. What is the best structure for Employee? Sorted table Heap table Heap table initially, then restructure to sorted table after bulk load is complete - Answers Heap table initially, then restructure to sorted table after bulk load is complete Sorted tables are always sorted on a single column. True False - Answers False If each bucket initially has one block, how many rows fit into a single bucket?