CMSC 424(A+ Guaranteed answers)

Average time to access block correct answers seekTime + 1000/rpm/2 *60 Average number of random I/O correct answers 1000/average time to access block Raid : Redundant Array of Independent Disks correct answers RAID 1: two disks are synched/mirroring preferred for higher updates and has better write perfomance RAID 5: better for higher amounts of data and better for reads RAID 5 Update Value x correct answers Read from P# and X Computer P#' = P# xor X xor X' Update P#' and X' RAID 5 Update X in Disk Failure if X in Disk correct answers Read all values except for disk Compute X = all Values xor Compute P#' = P# xor X xor X' Update p#' RAID 5 Update X in Disk Failure if P# in Disk correct answers Read x and P# cannot read P# write x' LRU/MRU correct answers Least Recently Used Most recently used pinning correct answers can't write block to disk while disk is pinned restrict times you can write back to disk force output correct answers forces contents of block to be written to disk Sorted: Mapping of tables to files correct answers records are stored in sequential order according to a search key Hash Index: Mapping of tables to files correct answers Hash function that's computed and utilized to specifiy which block of the file records should be placed in Buckets Primary Index correct answers Relation is sorted on search key (clustering) Prirmary indexed databases can be both dense and sparse Secondary Indexes correct answers Branching Relation is sorted based off of second level of indexing