Data compression apparatus, database system, data communication system, data compression method, storage medium and program transmission apparatus

摘要

It is one object of the present invention to perform data compression to encode the structure part of a document in a tree local language, such as XML or ASN.1. A data compression apparatus for encoding data and for compressing the encoded data comprises: a grammar rule 12 for a tree local language in which data are represented by a labeled tree structure; an encoder 11 for reading a document written in the tree local language, for dividing the document into a structure part and contents, and for encoding the structure part using the grammar rule 12 ; and a compressor 13 for compressing the contents of the document extracted by the encoder 11 , and for encoding the compressed contents.