1 trees.ps contains an explanation of the Genealogical Representation of Trees
2 in Databases which is being used in ldb_sqlite3. Note that we use fgID
3 representation with 4 bytes per level, so we can represent 6.5E+08 subclasses
4 of any object class. This should be adequate for our purposes. :-)
6 The following document is the primary basis for the schema currently being
7 used here: http://www.research.ibm.com/journal/sj/392/shi.html