Patent Document ID: 7814042
Application ID: 10920973

Base Claim:
1. A computer-implemented method of processing a query, comprising: determining a set of candidate queries for the query based on a particular candidate identification technique; wherein the particular candidate identification technique identifies as candidate queries fewer than all semantically equivalent queries that are determinable from transformations of one or more query blocks in the query; determining costs for each candidate query of the set of candidate queries; choosing a particular query, from the set of candidate queries, based on costs for each query in the set of candidate queries; wherein each candidate query in the set of candidate queries is semantically equivalent to the query; and executing the particular query in response to a request to execute the query; wherein the method is performed by one or more computing devices.

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Claim 10:
10. The method of claim 1 , further comprising determining the particular candidate identification technique from two or more candidate identification techniques that are available to a query-processing unit to process the query, wherein the two or more candidate identification techniques include an exhaustive query-processing technique that determines an initial set of candidate queries as all semantically equivalent queries that can be generated by the query-processing unit; and defines the set of candidate queries as all queries in the initial set of candidate queries; and chooses for the particular query a certain query that has a best cost of all queries in the initial set of candidate queries.