Invention Grant
- Patent Title: Distinct value estimation for query planning
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Application No.: US15943496Application Date: 2018-04-02
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Publication No.: US10853368B2Publication Date: 2020-12-01
- Inventor: Alexander Behm , Mostafa Mokhtar
- Applicant: Cloudera, Inc.
- Applicant Address: US CA Palo Alto
- Assignee: Cloudera, Inc.
- Current Assignee: Cloudera, Inc.
- Current Assignee Address: US CA Palo Alto
- Agency: Perkins Coie LLP
- Main IPC: G06F16/00
- IPC: G06F16/00 ; G06F16/2453 ; G06F16/2458 ; G06F16/835

Abstract:
The problem of distinct value estimation has many applications, but is particularly important in the field of database technology where such information is utilized by query planners to generate and optimize query plans. Introduced is a novel technique for estimating the number of distinct values in a given dataset without scanning all of the values in the dataset. In an example embodiment, the introduced technique includes gathering multiple intermediate probabilistic estimates based on varying samples of the dataset, 2) plotting the multiple intermediate probabilistic estimates against indications of sample size, 3) fitting a function to the plotted data points, and 4) determining an overall distinct value estimate by extrapolating the objective function to an estimated or known total number of values in the dataset.
Public/Granted literature
- US20190303479A1 DISTINCT VALUE ESTIMATION FOR QUERY PLANNING Public/Granted day:2019-10-03
Information query