Abstract: A database management system stores data form a plurality of logical tables as independent copies in different format. In one specific example the system organizes tables into table groups and de-normalizes the table in each table group. It also organizes data in a second format including vertical column containers that store all the data for one attribute, there being one column container for each table and each attribute within that table. The receipt of a query causes the system to develop a query plan that can interact with either or both of the container sets.

Abstract: A set of operators on group-structured data enable creation of efficient execution plans. These operators are of two (2) distinct types. They operate similarly. For each row that matches an input row type, an hkey is obtained. The hkey uniquely identifies a table row within a table group. The hkey is transformed into a modified hkey associated with an output row type. Starting with a row of interest associated with the modified hkey, a table group is probed to identify one or more additional rows. As the additional rows are identified, they are written into an output stream.