2026-09-22T03:10:14Z https://drops.dagstuhl.de/oai

oai:drops-oai.dagstuhl.de:26022 2026-09-05T19:34:56Z ddc:004 open_access

DeltaSort: Incremental Sorting of Arrays with Known Updates Dwivedi, Shubham Incremental sorting Sorting algorithms Array maintenance When records need to be read in a particular order, sorting at query time incurs repeated Θ(n log n) cost for an array of n records and can become a bottleneck in read-heavy workloads. A common solution is to maintain a derived sorted read-replica that is kept updated as the underlying system-of-record changes. For updating read-replicas that are stored as arrays, existing approaches rely on either full re-sorting or incremental algorithms such as binary insertion or merge-based sort. In this paper, we study incremental sorting under a new model in which the sorting routine is explicitly informed of the k indices updated since the previous sort - a setting that naturally arises in systems that track updates. Under this model, we present DeltaSort, a new algorithm that runs in O(n√k) expected time using O(k) auxiliary space under a random update model, and outperforms existing algorithms for small update batches in our experimental evaluation. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Shubham Dwivedi 2026 Is Part Of LIPIcs, Volume 371, 24th International Symposium on Experimental Algorithms (SEA 2026) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.SEA.2026.18 urn:nbn:de:0030-drops-260224 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SEA.2026.18 eng https://creativecommons.org/licenses/by/4.0/legalcode