Patent ID: 6532458
Filing Date: 2003-03-11
Classification: G06F,Y10S

Abstract:
A method for obtaining a sample in a single sequential pass of a plurality of records in a database system, the method comprising the steps of:(a) identifying the plurality of records and sampling semantics; (b) select a sampling operator based on the sampling semantics wherein the sampling operator comprises a probability function that outputs a number of times an input tuple should be included in the sample to obtain a sample according to the sampling semantics; and (c) obtaining a sample from the identified plurality of records using the sampling operator by: (i) inputing each of the plurality of records the sampling operator; and (ii) determining a number of times the record should be included in the sample based on the output of the sample operator; and (iii) selectively outputting the record for inclusion in the sample the determined number of times.