Hash tablosu: Revizyonlar arasındaki fark
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16. satır:
| sayfalar = 513–558
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</ref><ref name="cormen"
| authorlink = Thomas H. Cormen
| first = Thomas H.
| last = Cormen
| coauthors = [[Charles E. Leiserson|Leiserson, Charles E.]]; [[Ronald L. Rivest|Rivest, Ronald L.]]; [[Clifford Stein|Stein, Clifford]]
| title = [[Introduction to Algorithms]]
| publisher = MIT Press and McGraw-Hill
| year= 2001
| isbn = 978-0-262-53196-2
| edition = 2
| pages=221–252
| nopp = Chapter 11: Hash Tables
}}</ref>
Birçok durumda komut tablolarının [[arama ağaçları]] veya herhangi bir [[Çizelge (bilişim)|çizelge]] başvuru yapısından daha verimli olduğu ortaya çıkar. Bu sebeple birçok [[yazılım]] çeşidinde, özellikle [[birleşmeli dizin]]lerde, [[veritabanı indisi|veritabanı indislemesi]]nde, [[önbellek]]lerde ve [[küme veri yapısı|kümelerde]] kullanılır.
Satır 44 ⟶ 56:
Cryptographic hash functions are believed to provide good hash functions for any table size ''s'', either by modulo reduction or by bit masking. They may also be appropriate, if there is a risk of malicious users trying to [[denial of service attack|sabotage]] a network service by submitting requests designed to generate a large number of collisions in the server's hash tables.{{Citation needed|date=February 2007}}<!-- see discussion on talk page; just needs a reference --> <!-- However, these presumed qualities are hardly worth their much larger computational cost and algorithmic complexity, and the risk of sabotage can be avoided by cheaper methods (such as applying a secret [[salt (cryptography)|salt]] to the data, or using a [[universal hash function]]). -->
<!--Some authors claim that good hash functions should have the [[avalanche effect]]; that is, a single-bit change in the input key should affect, on average, half the bits in the output. Some popular hash functions do not have this property.<ref name="mulvey1">Bret Mulvey, [http://bretm.home.comcast.net/~bretm/hash/ Hash Functions]. Accessed April 11, 2009</ref> -->
<!-- === Perfect hash function ===
If all keys are known ahead of time, a [[perfect hash function]] can be used to create a perfect hash table that has no collisions. If [[minimal perfect hashing]] is used, every location in the hash table can be used as well.
Perfect hashing allows for constant time lookups in the worst case. This is in contrast to most chaining and open addressing methods, where the time for lookup is low on average, but may be very large (proportional to the number of entries) for some sets of keys. -->
== Kaynakça ==
{{kaynakça}}
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