1. An article of manufacture comprising: a data storage component; and stored by the data storage component, one or more segment group data structures, each including information about one or more types of transaction segment data items; each of a set of the segment group data structures resulting from one or more abstraction operations and including at least one of: a standard-based abstraction artifact; an item of pre-integration information; and an item that includes proprietary information; the article further comprising: stored by the data storage component, a segment combination data structure containing information extracted from a set of existing transaction data items, the segment combination data structure including one or more combinations of the segment group data structures, each segment group data structure including information about a respective type of transaction segment data items that occurs in the transaction data items; the segment combination data structure including two or more of the combinations of the segment group data structures, one of the two or more combinations being a union of segment group data structures in all the others; the segment combination data structure including a respective column for each of the two or more combinations and a respective row for each of the segment group data structures in the combination that is a union; the respective column of each of the combinations that is not a union including, in the respective row of one of the segment group data structures, an indication of whether the combination can include the one segment group data structure.