Database Reference
In-Depth Information
KEY TERMS AND DEFINITIONS
Categorizing Attribute:
an attribute that is used for partitioning the set of tuple into an ordered list
of mutually disjoint subcategories.
Category Cost:
an estimated cost of finding all relevant tuples by exploring the category tree, it
consists of the cost of visiting tuples in a leaf node, the cost of visiting intermediate nodes, and the cost
of visiting tuples in intermediate nodes if the user chooses to explore it.
Category Tree:
a labeled hierarchical category structure that is generated automatically based on
data clusters.
Data Cluster:
a closely-packed group of data tuples, the tuples in the same cluster are similar to
each other in semantic.
Query History:
the log of past user queries on the database, it can reflect the user preferences.
User Preferences:
an implicit need of a specific user for liking one thing.
Web Database:
a non-local autonomous database that is accessible only via a Web from-based interface.
