×

Reducing skew for database operation processing with randomization

  • US 10,545,923 B1
  • Filed: 12/19/2017
  • Issued: 01/28/2020
  • Est. Priority Date: 12/19/2017
  • Status: Active Grant
First Claim
Patent Images

1. A computer program, stored in a non-transitory computer-readable medium, on which is recorded a computer program, the computer program comprising executable instructions, that, when executed, perform a method for performing a database operation in a file system residing on a plurality of processing modules, the file system including a first relation having a plurality of first-relation entries, each of the plurality of first-relation entries having a first-relation attribute that is of interest in the database operation, the file system including a second relation having a plurality of second-relation entries, each of the plurality of second-relation entries having a second-relation attribute that is of interest in the computational operation, the method comprising:

  • setting a value of a distribution attribute in each of the first-relation entries to a unique value selected from among a domain of unique values;

    redistributing the first-relation entries of the first relation among the plurality of processing modules based on the first-relation attribute and the distribution attribute;

    making n copies of the second relation, where n is the number of unique values in the domain of unique values;

    redistributing each of the copies of the second relation to a respective processing module to which the first-relation entries of the first relation have been redistributed by;

    setting a number attribute for the second-relation entries for each respective copy of the second relation to a respective unique value selected from the domain of unique values, andredistributing each of the copies of the second relation based on the number attribute; and

    performing the computational operation to produce a result.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×