A Case for Fractured Mirrors
The Decomposition Storage Model (DSM) vertically partitions all attributes of a given relation. DSM has excellent I/O behavior when the number of attributes touched in the query is small. It also has a better cache footprint than the N-ary Storage Model (NSM) that is used by most database systems. However, DSM incurs a high cost in reconstructing the original tuple from the partitions. The authors first revisit some of the performance problems associated with DSM. They suggest a simple indexing strategy and compare different reconstruction algorithms.