1. A method, comprising: initializing a token statistics data structure, where the token statistics data structure is to store elements comprisinq a first entry to identify a token, and one or more of, a second entry to identify a sample period query frequency associated with the token, and a third entry to identify a fragmentation level associated with the token; updating the token statistics data structure with information related to a set of tokens associated with a set of queries processed during a sample period by a query processor; selecting a token to optimize based, at least in part, on information in the token statistics data structure, the token being selected based, at least in part, on determining that the value of a function based on both a sample period query frequency associated with a member of the set of tokens and a fragmentation level associated with the member of the set of tokens exceeds a desired level; estimating a fragmentation level of the database index based, at least in part, on the fragmentation level of one or more members of the set of tokens accessed most frequently during the sample period, where the database index includes one or more members of the set of tokens; and providing a signal concerning the token.