Flashcards
Hash Indexes
Cards in this deck (8)
- 1What is a hash index?A hash index is an index having a location mechanism based on:
- a hash function
- a hash table - 2Let h be the map h: key --> index page. Select the answers that fit the statement. The key space is the [domain/codomain] of h, and the address space is the [domain/codomain] of h.domain
codomain - 3True or False: in general, key space is usually much smaller than address space.False, the reverse is true.
- 4What is the key space of a hash function?The set of all possible values for keys
- 5What is the address space of a hash function?The set of all storage units (sets of pages)
- 6What is collision, with respect to hash functions?When two different keys are hashed into the same address
- 7With regards to hash indices, an equality search takes how many disk accesses on average? a) 1 b) 2 c) 3 d) equality searches are not supporteda) 1
- 8With regards to hash indices, a range search takes how many disk accesses on average? a) 1 b) 2 c) 3 d) range searches are not supportedd) range searches are not supported
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- File and Database Management Flashcards on Hash Indexes, created by Chuck H on 13/04/2019.
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- Chuck H
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