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Compression of Databases - Lesson Summary

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Arithmetic code

Arithmetic coding is a form of entropy encoding used in lossless data compression. Lossless compression has the property that the input sequence can be reconstructed exactly from the encoded sequence. Arithmetic coding is a nearly-optimal statistical coding technique that can produce a lossless encoding. Motivation for arithmetic coding is based on Shannon–Fano–Elias coding. Arithmetic coding is in principle a generalization of Shannon-Fano-Elias coding to coding symbol sequences instead of coding single symbols.

Compression of databases

Database compression is a set of techniques that reorganizes database content to save on physical storage space and improve performance speeds. A large number of compression schemes have been devised based on character encoding or detection of repetitive strings. A hush based scheme for compression of databases is based on the concept of the Universal hash family.