Squash takes multiple XML snapshots that are valid in consecutive periods of time and generates a single temporal XML document that contains all the content and temporal information of those snapshots. Note that even if all snapshots are individually valid, which should be checked separately, it is still necessary to run the TemporalValidator on the resulting temporal XML document to check the temporal constraints that the snapshots may have violated.
java Squash [config-file | snapshot-prefix starting-index ending-index [logical-annotation] [physical-annotation] ]
An XML file that describes the parameters to Squash. Parameters include the name of the logical annotation file, the name of the physical annotation file and the file names of the snapshots and their valid periods. If the config-file parameter is given, no other parameter are needed.
The prefix of file names of snapshots.
The range of the snapshot number. Snapshots are assumed to have the name generated by concatenating the snapshot_prefix, an integer between starting-index and ending-index, and the string ".xml". For example, if the snapshot prefix were "abc", the starting-index were 1, and the ending-index were 3, then the three snapshot files would be named "abc1.xml", "abc2.xml", and "abc3.xml". Snapshots are ordered by their valid periods, found in the cur_date attribute of the root element within each snapshot. The first snapshot can also be replaced by a temporal XML document containing the content of all snapshots that are valid before the second snapshot.
The logical annotation file describes which elements and attributes in a series of snapshots can evolve over time. If this argument is missing, the location of a logical annotation must be contained in the physical annotation file if it is present. If no logical annotation can be found, Squash generates a temporal XML document with time-varying root, implying any element or attribute can be time-varying.
The physical annotation file describes the elements and the attributes that can have timestamps. If this argument is missing, Squash generates a temporal XML document with time-varying root. The physical annotation may contain the location of the logical annotation file for the temporal XML document.