US 12,393,565 B2
Load unit conversion with unified persistence
Souvik Pal, Bengaluru (IN); Deepak Shrivastava, Pune (IN); Kantikumar Kantikumar, Bengaluru (IN); Janardhan Hungund, Pune (IN); Sebastian Seifert, Heidelberg (DE); Bernhard Scheirle, Leimen (DE); Amit Pathak, Pune (IN); Amit Saonerker, Pune (IN); and Amit Sankhla, Bengaluru (IN)
Assigned to SAP SE, Walldorf (DE)
Filed by SAP SE, Walldorf (DE)
Filed on Dec. 11, 2023, as Appl. No. 18/535,176.
Prior Publication US 2025/0190416 A1, Jun. 12, 2025
Int. Cl. G06F 16/00 (2019.01); G06F 12/1009 (2016.01); G06F 16/22 (2019.01)
CPC G06F 16/2282 (2019.01) [G06F 12/1009 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method performed by a database system, comprising:
detecting a first query targeting a first database object stored in a unified persistence format in a persistence store, wherein a first load unit is specified for loading the first database object into an in-memory store;
determining whether to convert the first load unit to a second load unit based on one or more conditions; and
responsive to determining to convert the first load unit to the second load unit for the first database object, loading the first database object into the in-memory store according to the second load unit without performing a rewrite of the first database object in the persistence store, wherein loading the first database object into the in-memory store according to the second load unit comprises:
creating a first column fragment object in the in-memory store, wherein the first column fragment object corresponds to the first database object;
incrementing a reference count associated with a first persistence page chain referenced by the first column fragment object and copying metadata associated with the first persistence page chain to the first column fragment object in response to creating the first column fragment object in the in-memory store;
instantiating, with the copied metadata, a first in-memory representation of the first persistence page chain; and
maintaining the first persistence page chain in the persistence store for as long as the reference count is greater than zero.