US 12,189,600 B2
Distributing rows of a table in a distributed database system
Knut Stolze, Hummelshain (DE); Luis Eduardo Oliveira Lizardo, Böblingen (DE); Reinhold Geiselhart, Rottenburg-Ergenzingen (DE); and Felix Beier, Haigerloch (DE)
Assigned to International Business Machines Corporation, Armonk, NY (US)
Filed by International Business Machines Corporation, Armonk, NY (US)
Filed on Feb. 18, 2021, as Appl. No. 17/178,618.
Prior Publication US 2022/0261389 A1, Aug. 18, 2022
Int. Cl. G06F 16/22 (2019.01); G06F 16/2455 (2019.01); G06F 16/901 (2019.01); H04L 67/10 (2022.01)
CPC G06F 16/2282 (2019.01) [G06F 16/24564 (2019.01); G06F 16/9017 (2019.01); H04L 67/10 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A computer implemented method for copying rows of a table across logical nodes in a distributed database system comprising for each logical node of a plurality of logical nodes:
connecting, by one or more computer processors, to a current logical node of the plurality of logical nodes;
selecting, by the one or more computer processors, one or more rows from one or more source nodes of the plurality of logical nodes to be stored in a target table on the current logical node, wherein the one or more rows are selected based on a distribution rule for distributing data in the distributed database system;
creating in each node of the plurality of logical nodes a physical target table for storing the rows associated to the plurality of logical nodes, wherein retrieving identified rows is performed from original tables;
adapting the distributed database system so that the distributed database system replaces a pushing step with a pulling step at the current logical node, wherein the pulling step is executed at the current logical node for performing the retrieving, and wherein the distributed database system comprises at each of the current logical node:
triggering execution of the row to node assignment step on each candidate source node, wherein the identified source nodes are nodes of the candidate source nodes that have identified the current logical node as target node; and
storing, by the one or more computer processors, the one or more rows into the target table, wherein the one or more rows are pulled from the one or more source nodes and stored in the current logical node.