Patent ID: 7949687

Claim:
A method of accessing data in a relational database system, comprising: receiving an instruction identifying a portion of a database table stored in the relational database system, wherein the portion includes a plurality of data elements, and a copy of one or more data elements of the portion is stored in each of a plurality of overlapping partitions within the relational database system, each partition among the plurality of overlapping partitions including a copy of one or more of the same columns or column segments of the database table, the plurality of overlapping partitions being created by the relational database system in response to an instruction identifying a set of columns to be included in the database table and specifying one or more columns to be included in multiple partitions; and in response to the instruction, identifying the plurality of overlapping partitions and reading the portion of the database table by accessing only a subset of the plurality of partitions, the subset of the plurality of overlapping partitions being chosen from among the plurality of overlapping partitions based on a determination of query efficiency made by a query optimizer.