Databases and Systems

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positional querying semantics, the integration algorithm, and the graphic display of
integrated maps.
Map Display
The MapView 2.0 Java applet currently used in GDB can display multiple maps
with alignment lines between common markers (figure 9).
Figure 9: MapView 2.0 shows the same region in several maps.
One problem with such displays is that the number of maps keeps increasing.
After doing a positional query the user is currently asked to select which of the maps
intersecting the query region they wish to see in the viewer. That list keeps getting
longer, and the user often has no intelligent basis for making the choice. We would
like to provide a robust default for this choice: an integrated map whose content
synthesizes that of all the other maps.
Integrated maps can be constructed based on piecewise-linear alignments. To
produce these maps the various universal coordinate localizations for a locus must be
combined into a single interval; at GDB we use a modified form of unioning which
throws out poor localizations that are consistent with tighter ones. The resulting
integrated or comprehensive map (figure 10) can be useful for certain purposes, but
must be treated with some skepticism. Anyone wanting detailed order information in
particular is well advised to look at the original maps, not the integrated one.