1. A computer-implemented method for executing search requests, the method comprising: receiving from a user a search request for travel reservation information, the search request including at least one first constraint to be met by results returned by a search; selecting at least one additional constraint not included in the search request; constructing a first query based on the at least one first constraint and the at least one additional constraint such that fewer search results are obtained in response to executing the first query than would be obtained in response to executing a query constructed without the at least one additional constraint; executing the first query to obtain first phase query results; providing the first phase query results for presentation to the user; constructing a second query that includes the at least one first constraint but does not include the at least one additional constraint; executing the second query to obtain second phase query results; and providing the second phase query results to update the presentation to the user and providing an indication to the user that the second phase query results are available, wherein the providing an indication to the user comprises presenting to the user a summary of the second phase query results without presenting the second phase query results.