A Storage Model to Bridge the Processor/Memory Speed Gap

This paper introduces Partition Attributes Across (PAX), a new layout for data records that combines the best of the two worlds and exhibits superior performance by eliminating unnecessary accesses to main memory. For a given relation, PAX stores the same data on each page as NSM. Within each page,however, PAX groups all the values of a particular attribute together on a minipage. During sequential scan(e.g., to apply a predicate on a fraction of the record), PAX fully utilizes the cache resources, because on each miss a number of the same attribute’s values are loaded into the cache together. At the same time, all parts of the record are on the same page. To reconstruct a record one needs to perform a mini-join among minipages, which incurs minimal cost because it does not have to look beyond the page.