Patent ID: 6125360
Filing Date: 2000-09-26
Classification: G06F,Y10S

Abstract:
A method for performing, after a batch window, an incremental refresh of a materialized view defined by a lossless one-to-n join, the method comprising the steps of:establishing a base table of the materialized view as a selected table;if the selected table is the right table of an outer join, then updating the materialized view to reflect deletions to the selected table by processing each row (Tj) that combines with a changed row in the selected table as followsif Tj only combines in the materialized view with changed rows of the selected table, then the rows in the materialized view that contain Tj are removed from the materialized view and replaced with a row in which selected columns are set to NULL; andif Tj combines in the materialized view with both changed and unchanged rows of the selected table, then the rows in the materialized view that result from Tj combining with changed rows are deleted, leaving only the rows in which Tj combines with unchanged rows of the selected table.