PPT-Hashing

Motivating Applications Large collection of datasets Datasets are dynamic insert delete Goal efficient searchinginsertiondeletion Hashing is ONLY applicable for exactmatch searching Direct Address Tables. Recently bit minwise hashing has been applied to largescale learning and sublinear time near neighbor search The major drawback of minwise hashing is the expensive pre processing as the method requires applying eg 200 to 500 permutations on the dat 1 Overview Hashing is a great practical tool with an interesting and su btle theory too In addition to its use as a dictionary data structure hashing also comes up in many di 64256erent areas including cryptography and complexity theory In this lectu The analysis uses only very basic and intuitively understandable concepts of probability theory and is meant to be accessible even for undergraduates taking their 64257rst algorithms course 1 Introduction dictionary is a data structure for storing a Management. 7. . course. Reminder. Disk. . and RAM. RAID . Levels. Disk. . space. management. Buffering. Heap. . files. Page. . formats. Record. . formats. Today. System . catalogue. Hash-based. Uri . Zwick. January 2014. Hashing. 2. Dictionaries. D .  . Dictionary() . – Create an empty dictionary. Insert(. D. ,. x. ) . – Insert item . x. into . D. Find(. D. ,. k. ) . – Find an item with key . COL 106. Shweta Agrawal, . Amit. Kumar. Slide Courtesy : Linda Shapiro, . Uwash. Douglas W. Harder, . UWaterloo. 12/26/03. Hashing - Lecture 10. 2. The Need for Speed. Data structures we have looked at so far. Martin Åkerblad. William . bruce. What is . Hashing?. Index. Key. 1. 2. 3. 4. 5. 6. 7. Key. 56. 84. 23. 42. 71. 97. 55. Hash. . function. 56. 42. 71. 23. 84. 55. 97. Value. When to use hashing.. Quick searching in large databases. CST203-2 Database Management Systems. Lecture 7. Disadvantages. on index structure:. We must access an index structure to locate data, or must use binary search, and that results in more I/O operations. Hashing & Partitioning. 1. Peng Sun. Server Load Balancing. Balance load across servers. Normal techniques: . Round-robin? . 2. Limitations of Round Robin. Packets of a single connection spread over several servers. Cyryptocurrency Project Proposal - Spring 2015. SHA Use in Bitcoin. SHA256 used heavily as bitcoin’s underlying cryptographic hashing function. Two examples (of many) are its use in the Merkle tree hash, as well as the proof of work calculation. Plan. I spent the last decade advising on numerous cases where hash tables/functions were used. A few observations on . What data structures I’ve seen implemented and where. What do developers think, were they need help. Consider a set of data with N data items stored in some data structure. We must be able to insert, delete & search for items. What are possible ways to do this? What is the complexity of each structure & method ?. Naifan Zhuang, Jun Ye, Kien A. Hua. Department of Computer Science. University of Central Florida. ICPR 2016. Presented by Naifan Zhuang. Motivation and Background. According to a report from Cisco, by 2019:. What is a hashing function?. Fingerprint for a given piece of data. Typically generated by a mathematical algorithm. Produces a fixed length string as its . output. Hashes are sometimes . called a . checksum or message digests.