US Patent 10108543 Efficient physical garbage collection using a perfect hash vector

Embodiments are directed to perfect physical garbage collection (PPGC) process that uses a perfect hash vector instead of large Bloom filters of the regular physical garbage collection process for the live and live instance vectors and consolidates both into a single live vector using the perfect hash vector. A method of PPGC includes an analysis phase walking an index containing a mapping of fingerprints to a container ID for a plurality of containers and building a perfect hash function for a walk vector and a live vector, wherein the live vector uses a perfect hash vector, an enumeration phase inserting live segments in memory into the perfect hash vector, a select phase traversing the plurality of containers and selecting containers that meet a defined liveness threshold and a copy phase copying live segments out of the selected containers.