Patent ID: 9104784
Filing Date: 2015-08-11
Classification: G06F

Abstract:
1. A computer-implemented method for detecting one or more multi-column composite key column sets by a processor, the method comprising: Accessing, by the processor, a plurality of first columns in a database, each first column representing a parameter, each first column comprising a set of distinct parameter values of its respective parameter, each distinct parameter value being stored in association with one or more object identifiers; selecting, by the processor, two or more of the first columns for use as a current candidate column set, the current candidate column set comprising at least a first and a second candidate column, the current candidate column set being of a current cardinality; determining, by comparing object-identifiers stored in association with parameter values of the candidate columns with each other, whether for the current candidate column set at least one tuple of parameter values exists with parameter values respectively stored in association with two or more shared ones of the object identifiers on a storage medium, whereby any tuple of parameter values comprises one parameter value of each candidate column of the current candidate column set; based on determining that the at least one tuple does not exist, identifying, by the processor, the current candidate column set as a multi-column composite key column set; and otherwise, replacing the second candidate column by another selected one of the first columns for creating a new current candidate column set with the current cardinality or adding the other selected one of the first columns to the current candidate column set for creating a new current candidate column set with a new current cardinality increased by one, the other first column not yet having been an element of a previously selected candidate column set of the current cardinality, and repeating the comparing.