1. A computer system for optimizing searches, the computer system comprising: one or more computer processors; one or more computer readable storage media; a search server including a search engine; and program instructions stored therein for execution by at least one of the one or more computer processors, the program instructions comprising instructions to: receive a boolean search query comprising a plurality of operands and corresponding operators and usage information corresponding to a user, wherein the usage information is stored in a cookie and comprises user browsing information, user language preferences, and user file type preferences; determine a search load of the search engine, wherein the search load includes an amount of resources of the search server that are being utilized; in response to determining that the search load is greater than a pre-defined threshold, determine modifications to be made to the boolean search query according to the usage information; modify the boolean search query according to the modifications; and perform a search using the modified boolean search query.