Attribute vector coding is the centerpiece of Xtreme Compression’s proprietary technology. It is a fixed-to-variable-length row-oriented vector transform methodology for compressing database tables with row/column structure. It breaks new ground by capturing and exploiting the innumerable interrelationships, functional dependencies, and statistical correlations in structured data without first having to solve the intractable problem of explicitly identifying and defining them.

Attribute vector coding achieves unequaled compression efficacy because it systematically models data at the highest levels of abstraction, across dimensions, and across data types. That modeling is typically more than an order of magnitude more complex than the subsequent encoding of the modeled data. That makes attribute vector coding far less subject than conventional methods to compressibility limits imposed by information theory.

Attribute vector coding works by first recovering a functional understanding of the systems and processes that create the source data. Using that, it computes structured predictions of table record field values, and expresses them, and differences between those predictions and actual data values, through a system of functions and residues. Those functions are designed to exploit interrelationships and statistical dependencies that are often too weak, complex, and/or numerous to be explicitly identified and defined. The functions, together with degenerated canonical Huffman codes for encoding them, decorrelate across dimensions, data types, and levels of abstraction simultaneously in order to exploit both inter-tuple and intra-tuple correlations.

Of course, theoretical advantages would all be for nought were attribute vector coding not cost-effective to use. That is why one other aspect is vital: flexibility. It is why attribute vector coding can systematically accommodate structured data regardless of data type, cardinality, skew, sparsity, or field width. That systematization minimizes the number of individual compression methods having to be developed, implemented, optimized, tested, and maintained in the delivered product in order to ensure that attribute vector coding is, above all, practical.