Compression of subdefinite data in 7-piece chess tables
Employees of MSU Computer Science department solved the problem of 7-man chess endings in 2012. This task is an example of utlra-high dimension problem (the total size of resulted data is about 1 Petabyte). One of the complex problems solved during the project is efficient block-oriented compression with providing high speed of random access. Initially popular LZMA algorithm was used for compression. It is considered as one of the most efficience. Nevetheless compression was improved further up to 35%. The efficiency was provided with data reodering before compression, compression by RE-PAIR algorithm and using the technique of so called subdefinite values. The article tells about implementation details of all compresson techniques used in the specified project.