MonetDB/X100 - A DBMS in the CPU cache

X100 is a new execution engine for the MonetDB system, that improves execution speed and overcomes its main memory limitation. It introduces the concept of in-cache vectorized processing that strikes a balance between the existing column-at-a-time MIL execution primitives of MonetDB and the tuple-at-a-time Volcano pipelining model, avoiding their drawbacks: intermediate result materialization and large interpretation overhead, respectively. We explain how the new query engine makes better use of cache memories as well as parallel computation resources of modern super-scalar CPUs. MonetDB/X100 can be one to two orders of magnitude faster than commercial DBMSs and close to hand-coded C programs for computationally intensive queries on in-memory datasets. To address larger disk-based datasets with the same efficiency, a new ColumnBM storage layer is developed that boosts bandwidth using ultra lightweight compression and cooperative scans.