Patent attributes
Methods and apparatus, including computer program products, implementing and using techniques for compressing data included in several transactions. Each transaction has at least one item. A unique identifier is assigned to each different item and, if taxonomy is defined, to each different taxonomy parent. Sets of transactions are formed from the several transactions. The sets of transactions are stored using a computer data structure including: a list of identifiers of different items in the set of transactions, information indicating number of identifiers in the list, and bit field information indicating presence of the different items in the set of transactions, said bit field information being organized in accordance with the list for facilitating evaluation of patterns with respect to the set of transactions. A data structure for compressing data included in a set of transactions is also provided.
