An efficient information search mechanism provides control over the
relaxation of a search query to users that are requesting searches.
Through such a mechanism, a user can specify a sequence of sub-queries
that is associated with variations of the main search criteria, and
specify a progression in which to execute the sub-queries. Hence, users
can impart their priorities with respect to search term variations used
in relaxing the main search criteria, which further allows the users to
impart their notion of the relevance of results that may be returned by
particular sub-queries. A query that includes a sequence of sub-queries
is received and the sub-queries are executed, if at all, by a database
server in an order based on the progression specified by the user.
Response time and network loading are improved through reduction of
unnecessary work by the database server and through reduction of
computationally costly communications between client and server and
associated processing.