Aspects of the subject matter described herein relate to buffering database server response data. In aspects, a database driver receives a request for data from a requester such as an application. Based on the request and information associated with a query, the database driver determines whether the requester is allowed to obtain data that has been previously buffered. If the database driver determines that the requester is not allowed to obtain data that has been previously buffered, the database driver indicates that blocks corresponding to the data may be freed. The database driver obtains new blocks from the database when they are needed. The database driver may determine whether to free blocks depending on a mode in which the blocks are accessed. When blocks are requested in a stream mode, they may be discarded once provided to a requester unless a bookmark has been set.