, 2002) along with the queries containing the attribute
KSEQ, in which case we substitute only the high cardinality attributes for KN so
that these queries contain only high cardinality attributes. Even though the HCAQS
is a subset of VHCAQS, a different PMap is obtained here as the additional attribute
KSEQ is included. The number of bits allotted to each property in the pstring
is different from the PMap generated for the HCAQS, as is the space consumption.
Table 8 shows the 12 queries in VHCAQS.
Property.Map
The PMap for this set of queries constitutes five properties on the five attributes
accessed in the queries. In this example, the dimensionality of the PMap index is 5
and pstring size is 11. For each query, the pmask, pfilterl, and pfilterh are shown in
Table 9. The properties in the VHCAQS PMap are as follows:
4 Davis & Gupta
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Idea Group Inc. is prohibited.
??? Property.1: Range property on K100k utilizing 2 bits: [0, 2), [2, 3), [3, 4) and
[4, 100000],
??? Property.2:.Range property on K10k utilizing 2 bits: [0, 2), [2, 3), [3, 4) and
[4, 10000],
??? Property.3:.Range property on K1k utilizing 2 bits: [0, 2), [2, 3), [3, 4) and
[4, 1000],
??? Property 4: Boolean property on ???K2 = 2??? utilizing 1 bit, and
??? Property.
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