hipsterDB is a toy key/value DBMS project that is designed to only return data as long as that data is not "mainstream". The system keeps track of how many times a key is accessed within a time window. If the number of accesses for a key goes above a threshold, then that key will be temporary "removed" from the database. When the number of recent accesses goes below that threshold (i.e., it has "gone out of style"), then the key is available again.
Hobby, Open Source