Figure 1 shows the index sizes using different
compression techniques. The widely-adopted VBE is
used to evaluate the present technique of converting
consecutive IDs to intervals in Ginix. Figure 1 compares
the original inverted index (denoted by InvIndex),
the inverted index compressed by VBE (denoted by
InvIndex+VBE), the present inverted index (denoted
by Ginix), and the present inverted index compressed
by VBE (denoted by Ginix+VBE) for both the DBLP
and PubMed datasets.