US 11,921,716 B1
Inexact timestamp range matching join for time series data (AS OF JOIN)
Hossein Ahmandi, Seattle, WA (US); Jayanta Das, Bellevue, WA (US); Joshua Klahr, San Carlos, CA (US); Boyung Lee, Kirkland, WA (US); Wenye Li, Bellevue, WA (US); Abdul Q. Munir, Bozeman, MT (US); and Yi Pan, San Jose, CA (US)
Assigned to Snowflake Inc., Bozeman, MT (US)
Filed by Snowflake Inc., Bozeman, MT (US)
Filed on Aug. 21, 2023, as Appl. No. 18/453,079.
Int. Cl. G06F 16/00 (2019.01); G06F 16/2453 (2019.01); G06F 16/2455 (2019.01); G06F 16/27 (2019.01)
CPC G06F 16/24537 (2019.01) [G06F 16/2456 (2019.01); G06F 16/278 (2019.01); G06F 16/24544 (2019.01)] 30 Claims
OG exemplary drawing
 
1. A method comprising:
parsing, by at least one hardware processor, a query to determine a plurality of data processing operations associated with the query, the plurality of data processing operations comprising an AS OF JOIN operation between first time series data in a first table and second time series data in a second table;
generating a query plan of the query, the query plan including a plurality of nodes corresponding to the plurality of data processing operations, and at least one node of the plurality of nodes corresponding to the AS OF JOIN operation;
modifying the at least one node corresponding to the AS OF JOIN operation to generate a modified query plan of the query, the modifying based on applying a UNION operation on at least a first portion of column data in the first table and the second table to obtain a combined table; and
scheduling execution of the query by at least one of a plurality of computing nodes based on the modified query plan.