Fast Table Joining in Relational Data Bases and Fast Row Retrieval
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
Fast row retrieval in relational data bases is possible by transferring the technique of known full text information retrieval systems with the concept of occurrences to relational data bases. Domain support is the key to efficiently processing equi-join, one of the most important operators of relational algebra. From a purely formalistic point of view, two tables (relations) are joined by considering a set of row pairs from both tables and by combining each row of the first table with each row of the second table, forming what mathematicians call a Cartesian product of two sets of rows. For equi-joins, selection from this product is made by an equal comparison on equal.