1. A method of compressing data, comprising compressing a block of data using one or more references to entries of a compression dictionary, the method further comprising: obtaining an initial compression dictionary and a separate secondary dictionary; determining at least one subpart of the secondary dictionary that correlates with the block of data to compress; updating the initial compression dictionary by inserting the determined at least one subpart therein, to obtain the compression dictionary used for compressing the block of data.
18. A method of encoding a block of structured data of a structured document, comprising obtaining a structure channel grouping structural information of the structured data and at least one value channel grouping content information that corresponds to the same structural information; and compressing at least one of the structure and value channels using the method of claim 1 .